Small molecule inhibitors of rotamase enzyme activity

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to neurotrophic compounds having an-affinity for FKBP-type immunophilins, their preparation and use as inhibitors of the enzyme activity associated with imtnunophilin proteins, and particularly inhibitors of peptidyl-prolyl isomerase or rotamase enzyme activity.

«

2. Description of the Prior Art

The term imtnunophilin refers to a number of proteins that serve as receptors for the principal immunosuppressant drugs, cyclosporin A (CsA), FKS06, and rapamycin. Known classes of immunophilins are cyclophilins, and FK506 binding proteins, such as FKBP.

Cyclosporin A binds to cyclophilin while FK506 and rapamycin bind to FKBP. These imtnunophilin-drug complexes interface with a variety of intracellular signal transduction systems, especially in the immune system and the nervous system.

Immunophilins are known to have peptidyl-prolyl

I isomerase (PPIase) or rotamase enzyme activity. it has been determined that rotamase activity has a role in the catalyzation of the interconversion of the cis and trans isomer of immunophilin proteins.

<img file="AU742575B2_D0001.tif" />

Itnmunoph.ilins were originally discovered and studied in immune tissue. It was initially postulated by those skilled in the art that inhibition of the immunophilins rotamase activity leads to the inhibition of T-cell proliferation, thereby causing the immunosuppressive action exhibited by immunosuppressive drugs such as cyclosporin A, FK506, and rapamycin. Further study has shown that the inhibition of rotamase activity, in and of itself, is not sufficient for immunosuppressant activity. Schreiber et al., Science,

1990 vol. 250 pp. 556-559. It has been shown that the immunophilin-drug complexes interact with ternary protein targets as their mode of action. Schreiber et al., Cell, 1991, vol. 66, pp. 807-815. In the case of

FKBP-FK506 and FKBP-CsA, the drug-immunophilin complexes bind to the enzyme calcineurin, inhibitory Tcell receptor signalling leading to T-cell proliferation. Similarly, the complex of rapamycin and FKBP interacts with the RAFT1/FRAP protein and ihhibits signalling from the IL-2 receptor.

Immunophilins have been found to be present at high concentrations in the central nervous system.

Immunophilins are enriched 10-50 times more in the central nervous system than in the immune system.

Within neural tissues, itnmunoph.ilins appear to influence neuronal process extension, nitric oxide synthesis, and neurotransmitter release.

It has been found that picomolar concentrations of an immunosuppressant such as FK506 and rapamycin stimulate neurite out growth in PC12 cells and sensory nervous, namely dorsal root ganglion cells (DRGs) Lyons et al., Proc, of Natl. Acad. Sci., 1994 vol. 91, pp. 3191-3195. In whole animal experiments, FK506 has been shown to stimulate nerve regeneration following facial nerve injury and results in functional recovery in animals with sciatic nerve lesions.

Surprisingly, it has been found that drugs with a high affinity for FKBP are potent rotamase inhibitors 15 causing a neurotrophic effect. Lyons et al. These findings suggest the use of immunosuppressants in treating various peripheral neuropathies and enhancing neuronal regrowth in the central nervous system (CNS). Studies have demonstrated that neurodegenerative 20 disorders such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis (ALS) may occur due to the loss, or decreased availability, of a neurotrophic substance specific for a particular*. population of neurons affected in the disorder.

Several neurotrophic factors effecting specific neuronal populations in the central nervous system have been identified. For example, it has been hypothesized that Alzheimer's disease results from a decrease or loss of nerve growth factor (NGF) . it has thus been proposed to treat Alzheimer's patients with exogenous nerve growth factor or other neurotrophic proteins such as brain derived nerve factor (BDNF), glial derived nerve factor, ciliary neurotrophic factor, and neurotropin-3 to increase the survival of degenerating neuronal populations.

, Clinical application of these proteins in various neurological disease states is hampered by difficulties in the delivery and bioavailability of large proteins to nervous system targets. By contrast, immunosuppressant drugs with neurotrophic activity are relatively small and' display, excellent bioavailability and specificity. However, when administered chronically, immunosuppressants exhibit a number of potentially serious side effects including nephrotoxicity, such as impairment of glomerular filtration and irreversible interstitial fibrosis (Kopp et al., 1991, J. Am. Soc. Nephrol. 1:162); neurological deficits, such as involuntary tremors, or non-specific cerebral angina such as non-localized headaches (De Groen et al., 1987, N. Engl. J. Med. 317:861); and vascular hypertension with complications resulting therefrom (Kahan et al., 19Θ9 N. Engl. J. Med. 321: 1725) .

In order to prevent the side effects associated with use of the immunosuppressant compounds, the present invention provides non-immunosuppressive

-5compounds containing small molecule FKBP rotamase inhibitors for promoting neuronal growth and regeneration in various neuropathological situations where neuronal repair can be facilitated including peripheral nerved damage by physical injury or disease state such as diabetes, physical damage to the central nervous system (spinal cord and brain) brain damage associated with stroke, and for the treatment of neurological disorders relating to neurodegeneration, including Parkinson’s disease, Alzheimer’s disease, and amyotrophic lateral sclerosis.

SUMMARY OF THE INVENTION

The present invention relates to a novel class of neurotrophic compounds • · :,.7: having an affinity for FKBP-type immunophilins. Once bound to this protein the • · · ♦ neurotrophic compounds are potent inhibitors of the enzyme activity associated • · · • · · «7.:* with immunophilin proteins and particularly rotamase enzyme activity, thereby • · · • · * * stimulating neuronal regeneration and outgrowth. A key feature of the compounds .....: 15 of the present invention is that they do not exert any significant immunosuppressive activity in addition to their neurotrophic activity. The • · · · *ί*”ί compounds used in the invention have an affinity for FKBP-type immunophilins * ’’* and inhibit rotamase activity of the immunophilins. The compounds are useful in • · · · ···· . treating neurological disorders where neurodegeneration is present.

<img file="AU742575B2_D0002.tif" />

14/11/01 »gcl 0624.tpe.doc,5

-6Accordingly in a first aspect the present invention relates to use of a neurotrophic compound of the formula:

<img file="AU742575B2_D0003.tif" />

<img file="AU742575B2_D0004.tif" />

or a pharmaceutically acceptable salt or hydrate thereof, where

Ri represents

- a C1-C9 straight or branched chain alkyl or alkenyl group optionally substituted with C3-C8 cycloalkyl,

- C3 or C5 cycloalkyl,

- C5-C7 cycloalkenyl, where said alkyl, alkenyl, cycloalkyl, or cycloalkenyl groups may be .··. ; optionally substituted with C1-C4 alkyl, C1-C4 alkenyl, or hydroxy, • · · ··* - or An, where An is selected from the group consisting of 1-naphthyl, 2• · · .’·*·. 15 naphthyl, 2-indolyl, 3-indolyl, 2-furyl, 3-furyl, 2-thiazolyl, 2-thienyl, 3-thienyl, 2-, 3-, • · · · : or 4-pyridyl, and phenyl, having one to three substituents which are independently • · · · :·.··. selected from the group consisting of hydrogen, halogen, hydroxyl, nitro, • · trifluoromethyl, C1-C6 straight or branched alkyl or alkenyl, C1-C4 alkoxy or C1-C4 ·:···: alkenyloxy, phenoxy, benzyloxy, and amino;

X is oxygen or sulfur;

Y is oxygen or NR2, where R2 is hydrgoen or C1-C6 alkyl; and • · · · ς,,.,ς Z represents • · · · ^: - a C2-C6 straight or branched chain alkyl or alkenyl, wherein the alkyl or •

alkenyl chain is substituted in one or more positions with An as defined above, 25 - C₃-C₈ cycloalkyl,

- cycloalkyl connected by a Ci-C₆ straight or unbranched alkyl or alkenyl chain, or

- Ar₂ where Ar₂ is selected from the group consisting of 2-indolyl, 3-indolyl,

2-furyl, 3-furyl, 2-thiazolyl, 2-thienyl, 3-thienyl, 2-, 3-, or 4-pyridyl, and phenyl,

<img file="AU742575B2_D0005.tif" />

having one to three substituents which are independently selected from the group

18/04/2001 ,cfl 0624^peci,6

-7 consisting of hydrogen, halogen, hydroxyl, nitro, trifluoromethyl, C1-C6 straight or branched alkyl or alkenyl, C1-C4 alkoxy or C1-C4 alkenyloxy, phenoxy, benzyloxy, and amino;

- the fragment:

--CH—U—X2-R4 where

R3 is selected from straight or branched Ci-Ce alkyl optionally substituted 10 with C3-C8 cycloalkyl or An as defined above, and unsubstitued An;

X₂ is O or NR5, where R5 is selected from hydrogen, C1-C6 straight or branched alkyl and alkenyl;

R4 is selected fro the group consisting of phenyl, benzyl, C1-C5 straight or branched alkyl or alkenyl, and C1-C5 straight or branched alkyl or alkenyl • · ♦ ·, ’·; 15 substituted with phenyl, for promoting neuronal growth and regeneration, for treating a neurological disorder, or for preventing neurodegeneration.

• · · · • · • · • · · · • · ·

:.: In a second aspect the present invention relates to use of a neurotrophic • · · · : compound of the formula:

<img file="AU742575B2_D0006.tif" />

<img file="AU742575B2_D0007.tif" />

or a pharmaceutically acceptable salt or hydrate thereof, where

R1 represents

- a C1-C9 straight or branched chain alkyl or alkenyl group optionally substituted with C3-C8 cycloalkyl,

- C3 or C5 cycloalkyl,

- C5-C7 cycloalkenyl,

<img file="AU742575B2_D0008.tif" />

18/04/2001 ,cfl O624.speci,7

-8where said alkyl, alkenyl, cycloalkyl, or cycloalkenyl groups may be optionally substituted with C1-C4 alkyl, C1-C4 alkenyl, or hydroxy,

- or An, where An is selected from the group consisting of 1-naphthyl, 2naphthyl, 2-indolyl, 3-indolyl, 2-furyl, 3-furyl, 2-thiazolyl, 2-thienyl, 3-thienyl, 2-, 3-, or 4-pyridyl, and phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen, halogen, hydroxyl, nitro, trifluoromethyl, C1-C6 straight or branched alkyl or alkenyl, C1-C4 alkoxy or C1-C4 alkenyloxy, phenoxy, benzyloxy, and amino;

Z represents

- a C2-C6 straight or branched chain alkyl or alkenyl, wherein the alkyl or alkenyl chain is substituted in one or more positions with Ah as defined above,

- C3-C8 cycloalkyl,

-cycloalkyl connected by a C1-C6 straight or unbranched alkyl or alkenyl chain, or

- Ar2 where Ar2 is selected from the group consisting of 2-indolyl, 3-indolyl,

2-furyl, 3-furyl, 2-thiazolyl, 2-thienyl, 3-thienyl, 2-, 3-, or 4-pyridyl, and phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen, halogen, hydroxyl, nitro, trifluoromethyl, C1-C6 straight or branched alkyl or alkenyl, C1-C4 alkoxy or C1-C4 alkenyloxy, phenoxy, benzyloxy, and amino, for promoting neuronal growth and regeneration, for treating a neurological disorder, or for preventing neurodegeneration.

In a third aspect the present invention relates to use of a neurotrophic compound of the formula:

<img file="AU742575B2_D0009.tif" />

or pharmaceutically acceptable salts or hydrates thereof,

<img file="AU742575B2_D0010.tif" />

is the fragment:

18/04/200 l.cfl O624.speci,8

-9 Ο --CH—U—X₂-R₄ where

R3 is selected from the group consisting of straight or branched Ci-Ce alkyl 5 optionally substituted with C3-C8 cycloalkyl or An as defined above, and unsubstituted An ;

X2 is 0 or NR5, where R₅ is selected from the group consisting of hydrogen, C1-C6 straight or branched alkyl and alkenyl;

R4 is selected from the group consisting of phenyl, benzyl, C1-C5 straight or 10 branched alkyl or alkenyl, and C1-C5 straight or branched alkyl or alkenyl substituted with phenyl, for promoting neuronal growth and regeneration, for treating a neurological disorder, or for preventing neurodegeneration.

• ··

In a third aspect the present invention relates to use of a neurotrophic Nglyoxyl prolyl ester compound of the formula:

• · · · • · · • · • · • · · ·

<img file="AU742575B2_D0011.tif" />

or a • · · · ·· · · • · · ♦ pharmaceutically acceptable salt or hydrate thereof, where

R1 represents

- a C1-C5 straight or branched chain alkyl or alkenyl group optionally substituted with C3-C6 cycloalkyl,

- or An, where An is selected from the group consisting of 2-furyl, 2-thienyl, and phenyl; and

X is selected from the group consisting of oxygen and sulfur;

Y is oxygen; and

Z represents

- a straight or branched chain alkyl or alkenyl, wherein the alkyl or alkenyl chain is substituted in one or more positions with An as defined above,

<img file="AU742575B2_D0012.tif" />

18/04/2001 ,cfl O624.speci,9

-10 - C3-C6 cycloalkyl, or

- Ar₂ where Ar₂ is selected from 2-, 3-, or 4-pyridyl, or phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen and C1-C4 alkoxy, for promoting neuronal growth and regeneration, for 5 treating a neurological disorder, or for preventing neurodegeneration.

In a fifth aspect the present invention relates to use of a neurotrophic compound of the formula:

<img file="AU742575B2_D0013.tif" />

or a pharmaceutically acceptable salt or hydrate thereof, where ; R1 represents • · · ··’ - a C1-C9 straight or branched chain alkyl or alkenyl group optionally • · · .····. 15 substituted with C3-C8 cycloalkyl, • · • · · · : - C3 or C5 cycloalkyl,

- C5-C7 cycloalkenyl, • · , where said alkyl, alkenyl, cycloalkyl, or cycloalkenyl groups may be optionally substituted with C1-C4 alkyl, C1-C4 alkenyl, or hydroxy,

- or Αη, where An is selected from the group consisting of 1-naphthyl, 2naphthyl, 2-indolyl, 3-indolyl, 2-furyl, 3-furyl, 2-thiazolyl, 2-thienyl, 3-thienyl, 2-, 3-, or 4-pyridyl, and phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen, halogen, hydroxyl, nitro, trifluoromethyl, C1-C6 straight or branched alkyl or alkenyl, C1-C4 alkoxy or C1-C4 alkenyloxy, phenoxy, benzyloxy, and amino;

X is oxygen or sulfur;

Y is oxygen or NR₂, where R₂ is hydrogen or C1-C6 alkyl; and

Z represents

- a C₂-C₆ straight or branched chain alkyl or alkenyl, wherein the alkyl or alkenyl chain is substituted in one or more positions with Αη as defined above,

<img file="AU742575B2_D0014.tif" />

18/04/2001 ,cfl O624.speci, 10

- C₃-C₈ cycloalkyl, ₆.

- cycloalkyl connected by a Ci-C₆ straight or unbranched alkyl or alkenyl chain, or

- Ar₂ where Ar₂ is selected from the group consisting of 2-indolyl, 3-indolyl,

2-furyl, 3-furyl, 2-thiazolyl, 2-thienyl, 3-thienyl, 2-, 3-, or 4-pyridyl, and phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen, halogen, hydroxyl, nitro, trifluoromethyl, Ci-Ce straight or branched alkyl or alkenyl, C1-C4 alkoxy or C1-C4 alkenyloxy, phenoxy, benzyloxy, and amino;

- the fragment:

<img file="AU742575B2_D0015.tif" />

X2-R4 where

R3 is selected from straight or branched Ci-C₈ alkyl optionally substituted with C3-C₈ cycloalkyl or An as defined above, and unsubstituted An;

X₂ is O or NR5, where R5 is selected from hydrogen, C1-C6 straight or • · · to branched alkyl and alkenyl;

ft ··

:.: R4 is selected from the group consisting of phenyl, benzyl, C1-C5 straight or • « to · : ’ branched alkyl or alkenyl, and C1-C5 straight or branched alkyl or alkenyl substituted with phenyl, in the preparation of a medicament for promoting neuronal growth and regeneration, for treating a neurological disorder, or for preventing neurodegeneration.

In a sixth aspect the present invention relates to use of a neurotrophic compound of the formula:

• to

<img file="AU742575B2_D0016.tif" />

<img file="AU742575B2_D0017.tif" />

18/04/200I,cfl0624.speci,l 1

-11aor a pharmaceutically acceptable salt or hydrate thereof, where .Ri represents

- a C1-C9 straight or branched chain alkyl or alkenyl group optionally substituted with C3-C8 cycloalkyl,

- C3 or C5 cycloalkyl,

- C5-C7 cycloalkenyl, where said alkyl, alkenyl, cycloalkyl, or cycloalkenyl groups may be optionally substituted with C1-C4 alkyl, C1-C4 alkenyl, or hydroxy,

- or An, where An is selected from the group consisting of 1-naphthyl, 2- naphthyl, 2-indolyl, 3-indolyl, 2-furyl, 3-furyl, 2-thiazolyl, 2-thienyl, 3-thienyl, 2-, 3-, or 4-pyridyl, and phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen, halogen, hydroxyl, nitro, trifluoromethyl, C1-C6 straight or branched alkyl or alkenyl, C1-C4 alkoxy or C1-C4 alkenyloxy, phenoxy, benzyloxy, and amino;

<img file="AU742575B2_D0018.tif" />

Z represents

- a C2-C6 straight or branched chain alkyl or alkenyl, wherein the alkyl or alkenyl chain is substituted in one or more positions with An as defined above,

- C3-C8 cycloalkyl,

-cycloalkyl connected by a Ci-Ce straight or unbranched alkyl or alkenyl

....: 20 chain, or

<img file="AU742575B2_D0019.tif" />

- Ar₂ where Ar₂ is selected from the group consisting of 2-indolyl, 3-indolyl,

2-furyl, 3-furyl, 2-thiazolyl, 2-thienyl, 3-thienyl, 2-, 3-, or 4-pyridyl, and phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen, halogen, hydroxyl, nitro, trifluoromethyl, C1-C6 straight or branched alkyl or alkenyl, C1-C4 alkoxy or C1-C4 alkenyloxy, phenoxy, benzyloxy, and amino, in the preparation of a medicament for promoting neuronal growth and regeneration, for treating a neurological disorder, or for preventing neurodegeneration.

18/04/200 l,cfl0624.spec Vi

-11bln a seventh aspect the present invention relates to use of a neurotrophic compound of the formula:

<img file="AU742575B2_D0020.tif" />

or pharmaceutically acceptable salts or hydrates thereof, where

Z is the fragment:

o

--CH—U—X₂-R₄ .··. : 1₃ • · · • · : 10 where • · · ·

R3 is selected from the group consisting of straight or branched Ci-Cs alkyl • · ·

·.· / optionally substituted with C3-C8 cycloalkyl or Αη as defined above, and • · · · : unsubstituted Αη; ,

X2 is 0 or NR5, where R5 is selected from the group consisting of hydrogen, * ’’15 C1-C6 straight or branched alkyl and alkenyl;

• · ' ’·.·.* R4 is selected from the group consisting of phenyl, benzyl, C1-C5 straight or • · · · branched alkyl or alkenyl, and C1-C5 straight or branched alkyl or alkenyl • · substituted with phenyl, in the preparation of a medicament for promoting neuronal • · · ’··* * growth and regeneration, for treating a neurological disorder, or for preventing * 20 neurodegeneration.

In an eighth aspect the present invention relates to use of a neurotrophic compound of the formula:

<img file="AU742575B2_D0021.tif" />

18/04/2001 ,cfl O624.speci,b

-11c-

<img file="AU742575B2_D0022.tif" />

<img file="AU742575B2_D0023.tif" />

or a pharmaceutically acceptable salt or hydrate thereof, where

Ri represents

- a C1-C5 straight or branched chain alkyl or alkenyl group optionally substituted with C3-C6 cycloalkyl,

- or An, where An is selected from the group consisting of 2-furyl, 2-thienyl, and phenyl; and

X is selected from the group consisting of oxygen and sulfur;

Y is oxygen; and

Z represents

- a straight or branched chain alkyl or alkenyl, wherein the alkyl or alkenyl

<img file="AU742575B2_D0024.tif" />

chain is substituted in one or more positions with An as defined above,

- C3-C6 cycloalkyl, or

- Ar₂ where Ar₂ is selected from 2-, 3-, or 4-pyridyl, or phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen and C1-C4 alkoxy, in the preparation of a medicament for promoting neuronal growth and regeneration, for treating a neurological disorder, or for preventing neurodegeneration.

In a ninth aspect the present invention relates to a method of promoting neuronal growth and regeneration, treating a neurological disorder, or preventing neurodegeneration which comprises administering a therapeutically effective amount of a neurotrophic compound of the formula:

<img file="AU742575B2_D0025.tif" />

<img file="AU742575B2_D0026.tif" />

or a pharmaceutically acceptable salt or hydrate thereof, where

Ri represents

<img file="AU742575B2_D0027.tif" />

18/04/2001 ,cfl O624.speci,c

- 11d - a C1-C9 straight or branched chain alkyl or alkenyl group Optionally substituted with C3-C8 cycloalkyl,

- C3 or C5 cycloalkyl,

- C5-C7 cycloalkenyl, where said alkyl, alkenyl, cycloalkyl, or cycloalkenyl groups may be optionally substituted with C1-C4 alkyl, C1-C4 alkenyl, or hydroxy,

- or Αη, where An is selected from the group consisting of 1-naphthyl, 2naphthyl, 2-indolyl, 3-indolyl, 2-furyl, 3-furyl, 2-thiazolyl, 2-thienyl, 3-thienyl, 2-, 3-, or 4-pyridyl, and phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen, halogen, hydroxyl, nitro, trifluoromethyl, C1-C6 straight or branched alkyl or alkenyl, C1-C4 alkoxy or C1-C4 alkenyloxy, phenoxy, benzyloxy, and amino;

X is oxygen or sulfur;

Y is oxygen or NR2, where R2 is hydrogen or C1-C6 alkyl; and

Z represents

- a C2-C6 straight or branched chain alkyl or alkenyl, wherein the alkyl or alkenyl chain is substituted in one or more positions with An as defined above,

- C3-C8 cycloalkyl,

-cycloalkyl connected by a C1-C6 straight or unbranched alkyl or alkenyl chain, or

- Ar2 where Ar2 is selected from the group consisting of 2-indolyl, 3-indolyl, 2-furyl, 3-furyl, 2-thiazolyl, 2-thienyl, 3-thienyl, 2-, 3-, or 4-pyridyl, and phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen, halogen, hydroxyl, nitro, trifluoromethyl, Ci-Ce straight or .····, 25 branched alkyl or alkenyl, C1-C4 alkoxy or C1-C4 alkenyloxy, phenoxy, benzyloxy, and amino;

- the fragment:

<img file="AU742575B2_D0028.tif" />

where

R3 is selected from straight or branched Ci-Ce alkyl optionally substituted with C3-C8 cycloalkyl or An as defined above, and unsubstituted An;

<img file="AU742575B2_D0029.tif" />

18/04/2001 ,cfl O624.speci,d

X₂ is 0 or NRs, where R5 is selected from hydrogen, C1-C6 straight or _: &lt;

-11e branched alkyl and alkenyl;

R4 is selected from the group consisting of phenyl, benzyl, C1-C5 straight or branched alkyl or alkenyl, and C1-C5 straight or branched alkyl or alkenyl substituted with phenyl;

in sufficient amounts to promote neuronal growth and regeneration, treat a neurological disorder, or prevent neurodegeneration.

In a tenth aspect the present invention relates to a method of promoting neuronal growth and regeneration, treating a neurological disorder, or preventing neurodegeneration which comprises administering a therapeutically effective amount of a neurotrophic compound of the formula:

• · • ··

<img file="AU742575B2_D0030.tif" />

<img file="AU742575B2_D0031.tif" />

or a pharmaceutically acceptable salt or hydrate thereof, where

Ri represents

- a C1-C9 straight or branched chain alkyl or alkenyl group optionally substituted with C3-C8 cycloalkyl,

- C3 or C5 cycloalkyl,

- C5-C7 cycloalkenyl, where said alkyl, alkenyl, cycloalkyl, or cycloalkenyl groups may be optionally substituted with C1-C4 alkyl, C1-C4 alkenyl, or hydroxy,

- or An, where An is selected from the group consisting of 1-naphthyl, 2naphthyl, 2-indolyl, 3-indolyl, 2-furyl, 3-furyl, 2-thiazolyl, 2-thienyl, 3-thienyI, 2-, 3-, or 4-pyridyl, and phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen, halogen, hydroxyl, nitro, trifluoromethyl, C1-C6 straight or branched alkyl or alkenyl, C1-C4 alkoxy or C1-C4 alkenyloxy, phenoxy, benzyloxy, and amino;

Z represents

<img file="AU742575B2_D0032.tif" />

18/04/200),cfl0624.speci,e

-11f -

- a C2-C6 straight or branched chain alkyl or alkenyl, wherein the alkyl or alkenyl chain is substituted in one or more positions with An as defined above,

- C3-C8 cycloalkyl,

-cycloalkyl connected by a C1-C6 straight or unbranched alkyl or alkenyl chain, or

- Ar₂ where Ar₂ is selected from the group consisting of 2-indolyl, 3-indolyl, 2-furyl, 3-furyl, 2-thiazolyl, 2-thienyl, 3-thienyl, 2-, 3-, or4-pyridyl, and phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen, halogen, hydroxyl, nitro, trifluoromethyl, Ci-C₆ straight or branched alkyl or alkenyl, C1-C4 alkoxy or C1-C4 alkenyloxy, phenoxy, benzyloxy, and amino, in sufficient amounts to promote neuronal growth and regeneration, treat a neurological disorder, or prevent neurodegeneration.

In an eleventh aspect the present invention relates to a method of promoting neuronal growth and regeneration, treating a neurological disorder, or preventing neurodegeneration which comprises administering a therapeutically effective amount of a neurotrophic compound of the formula:

• · • · • · • · · ♦ · » · • · · · ·· · · • · · · • · · · • ·

<img file="AU742575B2_D0033.tif" />

···· • · or pharmaceutically acceptable salts or hydrates thereof, where

Z is the fragment:

--CH—U—X₂-R₄ where

<img file="AU742575B2_D0034.tif" />

18/04/2001 ,cfl 0624.spec i,f

R3 is selected from the group consisting of straight or branched Ci-C8~alkyl optionally substituted with C3-C8 cycloalkyl or An as defined above, and unsubstituted Αη;

X₂ is 0 or NR5, where R5 is selected from the group consisting of hydrogen, 5 C1-C6 straight or branched alkyl and alkenyl;

R₄ is selected from the group consisting of phenyl, benzyl, C1-C5 straight or branched alkyl or alkenyl, and C1-C5 straight or branched alkyl or alkenyl substituted with phenyl, in sufficient amounts to promote neuronal growth and regeneration, treat a neurological disorder, or prevent neurodegeneration.

In a twelfth aspect the present invention relates to a method of promoting neuronal growth and regeneration, treating a neurological disorder, or preventing neurodegeneration which comprises administering a therapeutically effective amount of a neurotrophic compound of the formula:

• · · · • · · · • · · · • ·

<img file="AU742575B2_D0035.tif" />

<img file="AU742575B2_D0036.tif" />

or a pharmaceutically acceptable salt or hydrate thereof, where • · · · • · · · ·· · · • · · · ··

R1 represents

- a C1-C5 straight or branched chain alkyl or alkenyl group optionally substituted with C3-C6 cycloalkyl,

- or An, where An is selected from the group consisting of 2-furyl, 2-thienyl, and phenyl; and

X is selected from the group consisting of oxygen and sulfur;

Y is oxygen; and

Z represents

- a straight or branched chain alkyl or alkenyl, wherein the alkyl or alkenyl chain is substituted in one or more positions with Αη as defined above,

- C3-C6 cycloalkyl, or

<img file="AU742575B2_D0037.tif" />

18/04^2001,cfl0624.spec

- 11h- Ar₂ where Ar₂ is selected from 2-, 3-, or 4-pyridyl, or phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen and C1-C4 alkoxy, in sufficient amounts to promote neuronal growth and regeneration, treat a neurological disorder, or prevent neurodegeneration.

<img file="AU742575B2_D0038.tif" />

<img file="AU742575B2_D0039.tif" />

18/04/200 l.cil O624.speciji

Particularly preferred neurotrophic N-glyoxyl prolyl ester compounds according to the above formula are selected from the group consisting of:

3-(2,5-dimethoxyphenyl)-1-propyl (2S)-1- (3,3- dimethyl -1,2 -dioxopentyl) - 2 -pyrrolidinecarboxylate,

3- (2,5-dimethoxyphenyl) -l-prop-2- (E) -enyl (2S) -ΙΟ , 3-dimethyl-1,2-dioxopeiityl) -2-pyrrolidinecarboxylate,

2- (3,4,5-trimethoxyphenyl)-1-ethyl (2S)-1- (3,3- dime thy 1-1,2-dioxopentyl) -2-pyrrolidinecarboxylate,

3- (3-Pyridyl)-1-propyl (2S)-1-(3,3-dimethyl-1,2- dioxopentyl) -2-pyrrolidinecarboxylate,

3-(2-Pyridyl)-1-propyl (2S) -1-(3,3-dimethyl-i,2- dioxopentyl) -2-pyrrolidinecarboxylate,

3-(4-Pyridyl)-1-propyl (2S)-1-(3,3-dimethyl-1,2dioxopentyl) -2-pyrrolidinecarboxylate,

3-phenyl-1-propyl (2S)-1- (2-tert-butyl-l, 2dioxoethyl)-2-pyrrolidinecarboxylate,

3-phenyl-1-propyl (2S) .-1- (2-cyclohexylethyl-l, 225 dioxoethyl)-2-pyrrolidinecarboxylate,

3-(3-pyridyl)-1-propyl (2S)-1-(2-cyclohexylethyl-

1,2-dioxoethyl)-2-pyrrolidinecarboxylate,

3-(3-pyridyl)-1-propyl (2S)-1-(2-Cert-butyl-1,2-

<img file="AU742575B2_D0040.tif" />

dioxoethyl) - 2-pyrrolidinecarboxylate,

3.3- diphenyl-1-propyl (2S)-1- (3,3-dimethyl-1,2dioxopentyl) -2-pyrrolidinecarboxylate,

3-(3-pyridyl)-1-propyl (2S)-1-(2-cyclohexyl-1,25 dioxoethyl)-2-pyrrolidinecarboxylate,

3-(3-Pyridyl)-1-propyl (2S)-N-([2-thienyl] glyoxyl)pyrrolidinecarboxylate,

3.3- Diphenyl-1-propyl (2S) -1- (3,3-dimethyl-i,2dioxobutyl) -2-pyrrolidinecarboxylate,

3,3-Diphenyl-1-propyl (2S)-1-cyclohexylglyoxyl2-pyrrolidinecarboxylate, and

3,3 - Diphenyl -1 - propyl (2 S) -1 - (2 - thienyl) glyoxyl -

2-pyrrolidinecarboxylate.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a photomicrograph of chick dorsal root ganglia treated with various concentrations of Example 17 as indicated. Figure 1 shows that Example 17 of the present invention potently promotes neurite outgrowth in sensory neuronal cultures. Explant cultures isolated form embryonic.day 9-10 chick dorsal root ganglia were treated with various concentrations of Example 17 as indicated. . Forty-eight hours later·, the number of neurite with a length greater than one DRG explant was quantitated. The number of neurites .

expressed in untreated DRG's was subtracted form the neurite number of Example 17-treated samples to yield Example 17-dependent specific neurite outgrowth.

Micrographs of Example 17 treated DRG's, as well as quantitative dose-dependent neurite outgrowth elicited by Example 17 are presented.

Figure 2 is a graph showing quantitation of neurite outgrowth in chick dorsal root ganglia treated with various concentrations of Example 17 as indicated. Figure 2 shows that Example 17 of the present invention potently promotes neurite outgrowth in sensory neuronal cultures. Explant cultures isolated form embryonic day 9-10 chick dorsal root ganglia were treated with various concentrations of Example 17 as indicated. Forty-eight hours later, the number of neurite with a length greater, than one DRG explant was quantitated. The number of neurites expressed in untreated DRG's was subtracted form the neurite number of Example

17-treated samples to yield Example 17-dependent specific neurite outgrowth. Quantitative dose-dependent neurite outgrowth elicited by Example 17 is presented.

Figure 3 is a photomicrograph of rat sciatic nerve sections. Figure 3 shows that Example 1 of the present invention promotes neuronal regeneration following sciatic nerve lesions. Sciatic nerves of 150 g male Sprague-Dawley rats were crushed at the level of the hips. Example 1 (30 mg/kg s.c.), Inactive (30 mg/kg s.c.) or intralipid vehicle was administered once daily for the next 21 days. Animals were sacrificed, sciatic nerves removed and nerve segments 2 mm distal to the crush site were sectioned and stained with Holmes silver stain (to assess axon number) and Luxol fast blue (to assess remyelination). The micrographs show sciatic nerve sections of sham operated rats, vehicle-treated lesioned animals, Example 1 and Inactive treated at 630x magnification, four animals per group.

Figure 4 is a graph of [³H] -CFT binding per pg of Striatal Membrane Protein. Figure 4 shows that neuroimmunophilin ligands of the present invention promote recovery of dopamine neurons following MPTP treatment of mice. CD1 mice (25 g) were treated daily with 3 0 mg/kg MPTP (i.p.) for 5 days. The animals were also treated daily with intralipid vehicle, Example 1 (100 mg/kg s.c.) or Example 17 (40, 20, 10 mg/kg s.c., as indicated) concurrently with the MPTP and continued for an additional 5 days. After eighteen days, the mice were sacrificed, striata from 5 animals per group were pooled and processed into a washed membrane preparation. Binding of [3H]-CFT to these striated membrane preparations of various groups was quantitated to determine dopamine transporter levels on viable nerve terminals. Binding in the presence of 10 μΜ unlabelled CFT provided on estimate of nonspecific binding, which was subtracted from the total binding to quantitative specific [3H]-CFT bound. Binding was normalized to the protein content of the striatal membranes from each experimental group. Coronal and saggital brain sections from MPTP and drug treated animals were stained with anti-tyrosine hydroxylase (TH) Ig to quantitate striatal, medial forebrain bundle axonal and nigral levels of TH, which is indicative of functional dopaminergic neurons.

Figure 5 is a bar graph of pH] -CFT plotted for 200 pg of membrane protein. Figure 5 shows that neuroimmunophilin ligands of the present invention promote recovery of dopamine neurons following MPTP treatment of mice in accordance with the procedure described in Figure 4.

Figure 6 is a photomicrograph, at 630x magnification, of coronal and saggital brain sections. Figure 6 shows brain sections from MPTP and drug treated animals stained with anti-tyrosine hydroxylase (TH) Ig to quantitate striatal levels of TH, which is indicative of functional dopaminergic neurons.

Figure 7 is a photomicrograph, at 5Ox magnification, of coronal and saggital brain sections.

Figure 7 shows brain sections from MPTP and drug treated animals stained with anti-tyrosine hydroxylase (TH) Ig to quantitate nigral levels of TH, which is indicative of functional dopaminergic neurons.

Figure 8 is a photomicrograph, at 400x magnification, of coronal and saggital brain sections.

Figure 8 shows brain sections from MPTP and drug treated animals stained with anti-tyrosine hydroxylase (TH) Ig to quantitate medial forebrain bundle axonal levels of TH, which is indicative of functional dopaminergic neurons.

DETAILED DESCRIPTION· OF THE INVENTION

The novel neurotrophic compounds of this invention are relatively small molecules in relation to other known compounds which bind to FKBP-type immunoph.ilins, such as rapamycin, FK506, and cyclosporin.

The neurotrophic compounds of this invention have an affinity for the FK506- binding proteins such as 10 FKBP-12. When the neurotrophic compounds of the invention are bound to the FKBP, they have been found to unexpectedly inhibit the prolyl- peptidyl cis-trans isomerase activity, or rotamase activity of the binding protein and stimulate neurite growth, while not exhibiting an immunosuppressant effect.

More particularly, this invention relates to a novel class of neurotrophic compounds represented by the formula:

<img file="AU742575B2_D0041.tif" />

R¹

<td></td><td> Where R-| is a C-|-Cg straight or branched chain alkyl or alkenyl group optionally substituted with C3-C8 cycloalkyl, C3 or C5 cycloalkyl, C5-C7 cycloalkenyl, or Ar-j,</td>

<td> 5</td><td> where said alkyl, alkenyl, cycloalkyl or cycloalkenyl groups may be optionally substituted with C1-C4 alkyl, C1-C4 alkenyl, or hydroxy, and where Ar·, is selected from the group consisting of 1-napthyl, 2-napthyl, 2-indolyl, 3-indolyl, 2-furyl, 3furyl, 2-thienyl, 3-thienyl, 2-, 3- or 4-pyridyl, or phenyl, having one to three substituents which are independently selected from the group consisting of</td>

<td> ♦ · · ·. -.10 • · ·</td><td> hydrogen, halo, hydroxyl, nitro, trifluoromethyl, Cj-Cg straight or branched alkyl or</td>

<td> • · · • · · · • · · · • · • · · · • · · • · · • · · · ·· · · • · · • ·</td><td> alkenyl, C1-C4 alkoxy or C1-C4 alkenyloxy, phenoxy, benzyloxy, and amino; X is oxygen or sulfur; Y is oxygen or NR2, where R2 is hydrogen or Cq-C6 alkyl;</td>

<td> • · · · • · · ·· ·</td><td> and Z is a C2-Cg straight or branched chain alkyl or alkenyl, wherein the alkyl chain is substituted in one or more positions with Ar-| as defined above, C3-C8</td>

<td> • · · • · · • · · · • · · · • · • · · ·</td><td> cycloalkyl, cycloalkyl connected by a C-|-Cg straight or unbranched alkyl or alkenyl chain, or Ar2 where Ar2 is selected from the group consisting of 2-indolyl, 3-</td>

<td> » · · • · · » * · · •</td><td> indolyl, 2- furyl, 3-furyl, 2- thiazolyl, 2-thienyl, 3- thienyl, 2-, 3-, or 4-pyridyl, and phenyl, having one to three substituents which are independently selected from the</td>

<td> 20</td><td> group consisting of hydrogen, halo, hydroxyl, nitro, trifluoromethyl, C-|-Cg straight or branched alkyl or alkenyl, C1-C4 alkoxy or C1-C4 alkenyloxy, phenoxy, benzyloxy, and amino;</td>

15/06/99, Ip9427.pgsl8-19,18

Z may also be the fragment:

<img file="AU742575B2_D0042.tif" />

<img file="AU742575B2_D0043.tif" />

where R3 is selected from the group consisting of straight or branched alkyl Cq-Cg optionally substituted with C3-C3 cycloalkyl, or Arq as defined above, and unsubstituted Arq;

X2 is 0 or NR5, where R5 is selected from the

15/06/99, Ip9427.pgsl8-19,19 group consisting of hydrogen, C_x-C_s straight or branched alkyl and alkenyl;

R₄ is selected from the group consisting of phenyl, benzyl, C^Cj straight or branched alkyl or alkenyl, and Ci-Cs straight or branched alkyl or alkenyl substituted with phenyl; or pharmaceutically acceptable salts or hydrates thereof .

Preferred compounds have the following formula:

<img file="AU742575B2_D0044.tif" />

II where

R_x is a Ci.-C₉ straight or branched chain alkyl or alkenyl group optionally substituted with 15 C₃-C_a cycloalkyl, C₃ or C₅ cycloalkyl, C₅-C, cycloalkenyl, or Ar_x, where said alkyl, alkenyl, cycloalkyl or cycloalkenyl groups may be optionally substituted with Ci-C₄ alkyl, C_x-C₄ alkenyl, or hydroxy, and where Ar_x is selected from the group consisting of

1- napthyl, 2-napthyl, 2-indolyl, 3-indolyl,

2- furyl, 3-furyl, 2- thiazolyl, 2-thienyl, 3thienyl, 2-, 3-, or 4-pyridyl, or phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen, halo, hydroxyl, nitro, trifluoromethyl, C_x-C_s straight or branched alkyl or alkenyl, Οχ-ζ^ alkoxy or C,C₄ alkenyloxy, phenoxy, benzyloxy, and amino;

Z is a C₂-C₆ straight or branched chain alkyl . or alkenyl, wherein the alkyl chain is substituted in one or more positions with Ar_xas defined above, C3-C8 cycloalkyl, cycloalkyl connected by a Cx-C₆ straight or unbranched alkyl or alkenyl chain, or Ar₂where Ar₂ is selected from the group consisting of 2-indolyl, 3-indolyl, 2furyl, 3-furyl, 2- thiazolyl, 2-thienyl, 3thienyl, 2-, 3-, or 4-pyridyl, or phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen, halo, hydroxyl, nitro, trifluoromethyl, C_x-C₆ straight or branched alkyl or alkenyl, Cx-C₄ alkoxy or C,C« alkenyloxy, phenoxy, benzyloxy, and amino; or pharmaceutically acceptable salts or hydrates thereof.

Preferred neurotrophic

N-glyoxyl prolyl ester compounds have the formula:

<img file="AU742575B2_D0045.tif" />

<img file="AU742575B2_D0046.tif" />

where

R, is a Ci-C, straight or branched chain alkyl or alkenyl group optionally substituted with C₃ to C_s cycloalkyl, or Ar_x, where Ar_x is selected from the group consisting of 210 furyl, 2-thienyl, or phenyl;

X is selected from the group consisting of oxygen and sulfur;

Y is oxygen; and

Z is a straight or branched chain alkyl or alkenyl, wherein the alkyl chain is substituted in one or more positions with Ar_x as defined above, Cj-Cj cycloalkyl, Ar₂ where

Arj is selected from the group consisting of »1

2-, 3-, or 4-pyridyl, or phenyl, having one to three substituents which are independently selected from the group consisting of hydrogen and alkoxy.

The compounds of this invention exist as stereoisomeric forms, either enantiomers or diastereoisomers. The stereochemistry at position 1 (Formula 1) is R or S, with S preferred. Included within the scope of the invention are the enantiomers, 10 the racemic form, and diastereoisomeric mixtures.

Enantiomers as well as diastereoisomers can be separated by methods known to those skilled in the art.

It is known that immunophilins such as FKBP preferentially recognize peptide substrates containing 15 Xaa-Pro-Yaa motifs, where Xaa and Yaa are lipophilic amino acid residues. Schreiber et al. 1990 J. Org. Chem. 55, 4984-4986; Harrison and Stein, 1990 Biochemistry, 29, 3813-3816. Thus modified prolyl peptidomimetic compounds bearing lipophilic substituents should bind with high affinity to the hydrophobic core of the FKBP active site and inhibit its rotarnase activity.

Preferred compounds of the present invention in relation to the known shape and size of the hydrophobic core of the FKBP active site. Thus, very large and/or highly substituted R_x groups would bind include R_x groups which are not stereochemically bulky with less affinity to the FKBP active site.

Preferred compounds of the invention include:

3-phenyl-1-propyl (2S)-1- (3,3-dimethyl-i,2dioxopentyl) -2-pyrrolidinecarboxylate,

3-phenyl-1-prop-2-(E)-enyl (2S)-1-(3, 3-dimethyl-

1,2-dioxopentyl)-2-pyrrolidinecarboxylate,

3-(3,4,5-trimethoxyphenyl)-1-propyl (2S)-l-(3,3dimethyl-1,2-dioxopentyl)-2-pyrrolidinecarboxylate,

3-(3,4,5-trimethoxyphenyl)-l-prop-2-(E)-enyl (2S)-

1-(3,3-dimethyl-1,2-dioxopentyl)-2-pyrrolidine carboxylate,

3-(4,5-methylenedioxyphenyl)-1-propyl (2S)-1-(3,3. dimethyl-1,2-dioxopentyl) -2-pyrrolidinecarboxylate,

3-(4,5-methylenedioxyphenyl)-l-prop-2-(E) -enyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-2pyrrolidinecarboxylate,

3-cyclohexyl-1-propyl (2S)-1-(3,3 -dimethyl-1,2dioxopentyl)-2-pyrrolidinecarboxylate,

3-cyclohexyl-l-prop-2-(E)-enyl (2S)-1-(3,320 dimethyl-1,2-dioxopentyl) -2-pyrrolidinecarboxylate, (1R)-1,3-diphenyl-1-propyl (2S)-1-(3,3-dimethyl-

1,2-dioxopentyl)-2-pyrrolidinecarboxylate,

3-phenyl-1-propyl (2S)-1-(l,2-dioxo-2-[2furanyl])ethyl-2-pyrrolidinecarboxylate,

3-phenyl-1-propyl (2S)-1-(1,2-dioxo-2-[2thienyl]) ethyl-2-pyrrolidinecarboxylate,

3-phenyl-1-propyl (2S)-1-(l,2-dioxo-2-[2thiazolyl]) ethyl-2-pyrrolidinecarboxylate,

I

3-phenyl-1-propyl (2S)-1-(l,2-dioxo-2phenyl) ethyl-2-pyrrolidinecarboxylate,

3-(2,5-dimethoxyphenyl)-1-propyl (2S)-1- (3,3dimethyl-1,2-dioxopentyl) -2-pyrrolidinecarboxylate,

3-(2,5-dimethoxyphenyl)-l-prop-2-(E)-enyl (2S)-1 (3,3-dimethy 1-1,2-dioxopentyl) -2-pyrrolidinecarboxylate,

2- (3,4,5-trimethoxyphenyl)-1-ethyl (2S)-1- (3,3dimethyl-1,2-dioxopentyl) -2-pyrrolidinecarboxylate,

3- (3-Pyridyl)-1-propyl (2S)-1- (3,3-dimethyl-l,2dioxopentyl)-2-pyrrolidinecarboxylate,

3-(2-Pyridyl)-1-propyl (2S)-1- (3,3-dimethyl-l,2dioxopentyl)-2-pyrrolidinecarboxylate,

3-(4-Pyridyl)-1-propyl (2S)-1- (3,3-dimethyl-l,2dioxopentyl)-2-pyrrolidinecarboxylate,

3-phenyl-1-propyl (2S)-1- (2-cyclohexyl-l, 2dioxoethyl) -2-pyrrolidinecarboxylate,

3-phenyl-1-propyl (2S)-1- (2-ter t-butyl-1,2dioxoethyl)-2-pyrrolidinecarboxylate,

3-phenyl-1-propyl (2S)-1- (2-cyclohexylethyl-l,2- dioxoethyl)-2-pyrrolidinecarboxylate,

3-(3-pyridyl)-1-propyl (2S)-1- (2-cyclohexylethyl -

1,2-dioxoethyl)-2-pyrrolidinecarboxylate,

3-(3-pyridyl) -1-propyl (2S) -1- (2- tert-butyl-1,2dioxoethyl)-2-pyrrolidinecarboxylate,

3,3-diphenyl-1-propyl (2S)-1- (3,3-dimethyl-l,2dioxopentyl)-2-pyrrolidinecarboxylate,

3-(3-pyridyl)-1-propyl (2S)-1- (2-cyclohexyl-l,226 dioxoethyl)-2-pyrrolidinecarboxylate,

3-(3-Pyridyl)-1-propyl (2S)-N-([2-thienyl] glyoxyl)pyrrolidinecarboxylate,

3,3-Diphenyl-1-propyl (2S)-1-(3,3-dimethyl-l,2- dioxobutyl)-2-pyrrolidinecarboxylate,

3,3-Diphenyl-1-propyl (2S)-1-cyclohexylglyoxyl-

2-pyrrolidinecarboxylate,

3,3-Diphenyl-1-propyl (2S)-1- (2-thienyl)glyoxyl-

2-pyrrolidinecarboxylate.

Particularly preferred neurotrophic N-glyoxyl prolyl ester compounds are selected from the group consisting of:

3-(2,5-dimethoxyphenyl)-1-propyl (2S)-1- (3,3dimethyl-1,2-dioxopentyl) -2-pyrrolidinecarboxylate,

3-(2,5-dimethoxyphenyl)-l-prop-2-(E)-enyl (2S)-1(3,3-dimethyl-1,2-dioxopentyl) -2-pyrrolidinecarboxylate,

2- (3,4,5-trimethoxyphenyl)-1-ethyl (2S)-1- (3,3dimethyl-1,2-dioxopentyl) -2-pyrrolidinecarboxylate,

3-(3-Pyridyl)-1-propyl (2S)-1-(3,3-dimethyl-l,2dioxopenty 1) - 2 -pyrrol idinecarboxylate,

3- (2-Pyridyl)-1-propyl (2S)-1-(3,3-dimethyl-l,2dioxopentyl) -2 -pyrrolidinecarboxylate,

3-(4-Pyridyl)-1-propyl (2S)-1-(3,3-dimethyl-l,225 dioxopentyl)-2-pyrrolidinecarboxylate,

3-phenyl-1-propyl (2S) -1- (2- tert-butyl-1,2dioxoethyl) -2-pyrrolidinecarboxylate,

3-phenyl-1-propyl (2S)-1- (2-cyclohexylethyl-1,227 dioxoethyl) -2 -pyrrolidinecarboxylate,

3- (3-pyridyl) -1-propyl (2S) -1- (2-cyclohexylethyl-

1,2-dioxoethyl) -2-pyrrolidinecarboxylate,

3-(3-pyridyl)-1-propyl (2S)-1-(2-tert-butyl-1,25 dioxoethyl) -2-pyrrolidinecarboxylate,

3,3 - diphenyl -1 -propyl (2S)-l-(3,3 - dimethyl -1,2dioxopentyl) -2-pyrrolidinecarboxylate,

3-(3-pyridyl)-1-propyl (2S)-1-(2-cyclohexyl-1,2dioxoethyl) -2 -pyrrolidinecarboxylate,

3- (3-Pyridyl) -1-propyl (2S) -N- ( [2-thienyl] glyoxyl)pyrrolidinecarboxylate,

3,3 -Diphenyl -1 -propyl (2S) -1 - (3,3 -dimethyl-1,2dioxobutyl) -2-pyrrolidinecarboxylate,

3,3 - Diphenyl-1-propyl (2S) -1-cyclohexylglyoxyl -

2-pyrrolidinecarboxylate, and

3,3-Diphenyl-1-propyl (2S) -1-(2-thienyl)glyoxyl-

2-pyrrolidinecarboxylate.

The compounds of the present invention can be used in the- form of salts derived from inorganic or organic 20 acids and bases. Included among such acid salts are the following: acetate, adipate, alginate, aspartate, benzoate, benzenesulfonate, bisulfate butyrate, citrate, camphorate, camphor sulf onate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptanoate, glycerophosphate, heraissulfate heptanoate, hexanoate, hydrochloride, hydrobromide, hydroiodide, 228 hydroxyethanesulfonate, lactate, maleate, methanesulfonate, 2-naphthalensulfonate, nicotinate, oxalate, pamoate, pectinate, propionate, succinate, tartrate, thiocyanate, tosylate and undecanoate. Base 5 salts include ammonium salts, alkali metal salts such as sodium and potassium salts, alkaline earth metal t salts such as calcium and magnesium salts, salt with organic bases such as dicyclohexylamine salts, Nmethyl-D-glucamine, and salts with amino acids such as arginine, lysine, and so forth. Also, the basic nitrogen-containing groups can be quarternized with such agents as lower alkyl halides, such as methyl, ethyl, propyl, and butyl chloride, bromides and iodides; dialkyl sulfates like dimethyl, diethyl, dibutyl and diamyl sulfates, long chain halides such as decyl, lauryl, myristyl and stearyl chlorides, bromides and iodides, aralkyl halides like benzyl and phenethyl bromides and others. Water or oil-soluble or dispersible products are thereby obtained.

The neurotrophic compounds of this invention can be periodically administered to a patient undergoing treatment for neurological disorders or for other reasons in which it is desirable to stimulate neuronal regeneration and growth, such as in various peripheral neuropathic and neurological disorders relating to neurodegeneration. The compounds of this invention can also be administered to mammals other than humans for treatment of various mammalian neurological disorders.

<img file="AU742575B2_D0047.tif" />

The novel compounds of the present invention are potent inhibitors of rotamase activity and possess an excellent degree of neurotrophic activity. This activity is useful in the stimulation of damaged neurons, the promotion of neuronal regeneration, the prevention of neurodegeneration, and in the treatment of several neurological disorders known to be associated with neuronal degeneration and peripheral neuropathies. The neurological disorders that may be 10 treated include but are not limited to: trigeminal neuralgia, glossopharyngeal neuralgia, Bell's Palsy, myasthenia gravis, muscular dystrophy, amyotrophic lateral sclerosis, progressive muscular atrophy, progressive bulbar inherited muscular atrophy, herniated, ruptured or prolapsed invertabrae disk syndromes, cervical spondylosis, plexus disorders, thoracic outlet destruction syndromes, peripheral neuropathic such as those caused by lead, dapsone, ticks, prophyria, or Gullain-Barrfi syndrome,

Alzheimer's disease, and Parkinson's disease.

For these purposes the compounds of the present invention may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir in 25 dosage formulations containing conventional non-toxic pharmaceutically-acceptable carriers, adjuvants and vehicles. The term parenteral as used herein includes subcutaneous, intravenous, intramuscular, intraperitoneally, intrathecally, intraventricularly, intrasternal and intracranial injection or infusion techniques. .

To be effective therapeutically· as central nervous system targets the immunophilin-drug complex should readily penetrate the blood-brain barrier when peripherally administered. Compounds of this invention which cannot penetrate the blood-brain barrier can be effectively administered by an intraventricular route.

The pharmaceutical compositions may be in the form of a sterile injectable preparation, for example as a sterile injectable aqueous or oleaginous suspension. This suspension may be formulated according to techniques know in the art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterallyacceptable diluent or solvent, for example as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglycerides. Fatty acids such as oleic acid and its glyceride derivatives find use in the preparation of injectables, olive oil or castor oil, especially in their

<img file="AU742575B2_D0048.tif" />

polyoxyethylated versions . These oil solutions or suspensions may also contain a long-chain alcohol diluent or dispersant.

The compounds may be administered orally in the form of capsules or tablets, for example, or as an aqueous suspension or solution. In the case of tablets for oral use, carriers which are commonly used include lactose and corn starch. Lubricating agents, such as magnesium stearate, are also typically added. For oral administration in a capsule form, useful diluents . include lactose and dried com starch. When aqueous suspensions are required for oral use, the active ingredient is combined with emulsifying and suspending agents. If desired, certain sweetening and/or flavoring and/or coloring agents may be added.

The compounds of this invention may also be administered in the form of suppositories for rectal administration of the drug. These compositions can be prepared by mixing the drug with a suitable non20 irritating excipient which is solid at room temperature but liquid at rectal temperature and therefore will melt in the rectum to release the drug. Such materials include cocoa butter, beeswax and polyethylene glycols.

The compounds of this invention may also be administered optically, especially when the conditions addressed for treatment involve areas or organs readily accessible by topical application, including neurological disorders of the eye, the skin, or the lower intestinal tract.

Suitable topical formulations are readily prepared for each of these areas.

For ophthalmic use, the compounds can be formulated as micronized .suspensions in isotonic, pH adjusted sterile saline, or, preferably, as solutions is isotonic, pH adjusted sterile saline, either with or without a preservative such as benzylalkonium chloride.

Alternatively for the ophthalmic uses the compounds may be formulated in an ointment such as petrolatum.

For application topically to the skin, the compounds can be formulated in a suitable ointment containing the compound suspended or dissolved in, for example, a mixture with one or more of the following:

mineral oil, liquid petrolatum, white petrolatum, propylene glycol, polyoxyethylene polyoxypropylene compound, emulsifying wax and water.

the compounds can be formulated in a cream containing the active compound dissolved in, for example, a mixture the following: mineral oil, sorbitan

Alt ernat ively, suitable lotion or suspended or of one or more of monostearate, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2octyldodecanol, benzyl alcohol and water.

Topical application for the lower intestinal tract an be effected in a rectal suppository formulation (see above) or in a suitable enema formulation.

Dosage levels on the order of about .lmg to about

10,000 mg. of the active ingredient compound are useful in the treatment of the above conditions, with preferred levels of about 0 . lmg to about 1,000 mg. The amount of active ingredient that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode' of administration.

It is understood, however, that a specific dose level for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, rate of excretion, drug combination, and the severity of the particular disease being treated and form of administration.

The compounds can be administered with other neurotrophic agents such as neurotrophic growth factor (NGF), glial derived growth factor, brain derived growth factor, ciliary neurotrophic factor, and neurotropin-3. The dosage level of other neurotrophic drugs will depend upon the factors previously stated and the neurotrophic effectiveness of the drug combination.

E_t Test Procedure

Inhibition of the peptidyl-prolyl isomerase^-· (rotamase) activity of the inventive compounds can be 25 evaluated by known methods described in the literature (Harding, M.W. et al. Nature 341: 758-760 (1989); Holt et al. J. Am. Chem. Soc. 115: 9923-9938). These values are obtained as apparent K/s and are presented in

Table I. The cis-trans isomerization of an alanineproline bond in a model substrate, N-succinyl-Ala-AlaPro-Phe-p-nitroanilide, is monitored spectrophotometrically in a chymotrypsin-coupled assay, which releases para-nitroanilide from the trans form of the substrate. The inhibition of this reaction caused by the addition of different concentrations of inhibitor is determined, and the data is analyzed as a change in first-order rate constant as a function of inhibitor concentration to yield the apparent K_£values. .

In a plastic cuvette are added 950 mL of ice cold assay buffer (25 mM HEPES, pH 7.8, 100 mM NaCl), 10 mL of FKBP (2.5 mM in 10 mM Tris-Cl pH 7.5, 100 mM NaCl, 1 15 mM dithiothreitol), 25 mL of chymotrypsin (50 mg/ml in mM HC1) and 10 mL of test compound at various concentrations in dimethyl sulfoxide. The reaction is initiated by the addition of 5 mL of substrate (succinyl-Ala-Phe-Pro-Phe-para-nitroanilide, 5 mg/mL in 20 2.35 mM LiCl in trifluoroethanol). .

The absorbance at 390 nm versus time is monitored for 90 sec using a spectrophotometer and the rate . constants are determined from the absorbance versus time data files.

The data for these experiments is presented inTable I.

Table I

<img file="AU742575B2_D0049.tif" />

<td></td><td> No. 1</td><td> R 1,1-dimethylpropyl</td><td colspan="2"> R' 3-phenylpropyl</td><td> Kx 42</td>

<td> 5</td><td> 2</td><td> fl</td><td> 3 -pheny1-prop - 2(E)-enyl</td><td> 125</td><td></td>

<td></td><td> 3</td><td> M</td><td> 3-(3,4,5-trimethoxyphenyl) propyl</td><td> 200</td><td></td>

<td></td><td> 4</td><td> It</td><td> 3-(3,4,5-trimethoxy-</td><td></td><td></td>

<td> 10</td><td> 5</td><td> M</td><td> phenyl) -prop-2 -(E)-enyl 3- (4,5-methylenedioxy) phenylpropyl</td><td> 65</td><td> 170</td>

<td></td><td> 6</td><td> If</td><td> 3- (4,5-methylenedioxy) phenylprop-2- (E)-enyl</td><td> 160</td><td></td>

<td> 15</td><td> 7</td><td> It</td><td> 3 - cyclohexylpropyl</td><td></td><td> 200</td>

<td></td><td> 8</td><td> II</td><td> 3-cyclohexylprop-2- (E) enyl</td><td></td><td> 600</td>

<td></td><td> 9</td><td> If</td><td> (1R) -1,3-diphenyl-1propyl</td><td></td><td> 52</td>

<td> 20</td><td> 10</td><td> 2-furanyl</td><td> 3 -phenylpropyl</td><td></td><td> 4000</td>

<td></td><td> 11</td><td> 2-thienyl</td><td> M</td><td rowspan="2"> 100</td><td> 92</td>

<td></td><td> 12</td><td> 2-thiazolyl</td><td> Π</td><td rowspan="2"> 1970</td>

<td></td><td> 13</td><td> phenyl</td><td> n</td><td></td>

<td></td><td> 14</td><td rowspan="2"> 1,1-dimethylpropyl</td><td> 3-(2,5-dimethoxy)</td><td></td><td></td>

<td> 25</td><td></td><td> phenylpropyl</td><td></td><td> 250</td>

<td></td><td> 15</td><td> rt</td><td> 3-(2,5-dimethoxy) phenylprop-2-(E)-enyl</td><td> 450</td><td></td>

<td></td><td> 16</td><td> II</td><td> 2-(3,4,5-trimethoxy phenyl) ethyl</td><td></td><td> 120</td>

<td> 30</td><td> 17</td><td> II</td><td> 3-(3 -pyridyl) propyl</td><td></td><td> 5</td>

<td></td><td> 18</td><td></td><td> 3- (2-pyridyl) propyl</td><td></td><td> 195</td>

<td></td><td> 19</td><td> 0·</td><td> 3-(4-pyridyl) propyl</td><td></td><td> 23</td>

<td></td><td> 20</td><td> cyclohexyl</td><td> 3 -phenylpropyl</td><td> 82</td><td></td>

<td></td><td> 21</td><td> tert-butyl</td><td> n</td><td> 95</td><td></td>

<td> 35</td><td> 22</td><td> cyclohexyle thy1</td><td> If</td><td> 1025</td><td></td>

<td></td><td> 23</td><td> cyclohexylethyl</td><td> 3-(3-pyridyl) propyl</td><td> 1400</td><td></td>

<td></td><td> 24</td><td> tert-butyl</td><td> 3-(3-pyridyl) propyl</td><td> 3</td><td></td>

<td></td><td> 25</td><td> 1,1-dimethylpropyl</td><td> 3,3-diphenylpropyl</td><td></td><td> 5</td>

<td></td><td> 26</td><td> cyclohexyl</td><td> 3-(3-pyridyl) propyl</td><td> 9</td><td rowspan="2"> 1000</td>

<td> 40</td><td> 27</td><td> 2-thienyl</td><td> 3-(3-pyridyl) propyl</td><td></td>

<td></td><td> 28</td><td> tert-butyl</td><td> 3,3-diphenylpropyl</td><td> 5</td><td></td>

<td></td><td> 29</td><td> cyclohexyl</td><td> It</td><td> 20</td><td rowspan="2"> 150</td>

<td></td><td> 30</td><td> 2-thienyl</td><td> n</td><td></td>

In mammalian cells, FKBP-12 complexes with the inositol triphosphate receptor (IP₃R) and the ryanodine receptor (RyR). It is believed that the neurotrophic compounds of this invention disassociates FKBP-12 from 5 these complexes causing the calcium channel to become leaky (Cameron et al., 1995). Calcium fluxes are involved in neurite extensions so that the IP₃R receptor and the ryanodine receptor might be involved in the neurotrophic effects of drugs. Since the drugs bind to the same site as FKBP-12 as the IP₃R receptor, one could assume that the drugs displace the channels from FKBP-12.

Chick Dorsal Root Ganglion Cultures and Neurite Outgrowth.

Dorsal root ganglia were dissected from chick embryos of ten day gestation. Whiole ganglion explants were cultured on thin layer Matrigel-coated 12 well plates with Liebovitz L15 plus high glucose media supplemented with 2mM glutamine and 10% fetal calf serum, and also containing 10 μΜ cytosine β-Ώ araHinnfm-anoside (Ara C) at 37°C in an environment containing 5% CO₂. Twenty-four hours later, the DRGs were treated with various concentrations of nerve* growth factor, immunophilin ligands or combinations of

NFG plus drugs. Forty-eight hours after drug treatment, the ganglia were visualized under phase contrast or Hoffman Modulation contrast with a Zeiss Axiovert inverted microscope. Photomicrographs of the explants were made, and neurite outgrowth was quantitated. Neurites longer than the DRG diameter were counted as positive, with total number of neurites quantitated per each experimental condition. Three to four DRGs are cultured per well, and each treatment was performed in duplicate.

The data for these experiments are presented in

Table II. Representative photomicrographs for Example are shown in Figure 1; a dose response curve for this Example is given in Figure 2.

TABLE II

Neurite Outgrowth in Chick DRG

<td colspan="2"> Example No.</td><td> ED_S0, :</td>

<td></td><td> 1</td><td> 53</td>

<td> 15</td><td> 2</td><td> 105</td>

<td></td><td> 3</td><td> 149</td>

<td></td><td> 4</td><td> 190</td>

<td></td><td> 5</td><td> 10</td>

<td></td><td> 6</td><td> 75</td>

<td> 20</td><td> 10</td><td> 0.46</td>

<td></td><td> 11</td><td> 0.015</td>

<td></td><td> 14</td><td> 2</td>

<td></td><td> 15</td><td> 0.8</td>

<td></td><td> 16</td><td> 0.015·</td>

<td> 25</td><td> 17</td><td> 0.05</td>

<td></td><td> 18</td><td> 30</td>

<td></td><td> 19</td><td> 6</td>

<td></td><td> 20</td><td> 0.13</td>

<td></td><td> 21</td><td> 0.025</td>

<td> 30</td><td> 22</td><td> 0.66</td>

<td></td><td> 23</td><td> 1100</td>

<td></td><td> 24</td><td> 0.014</td>

<td></td><td> 25</td><td> 0.50</td>

<td></td><td> 26</td><td> 2</td>

<td> 35</td><td> 27</td><td> 500</td>

<td></td><td> 28</td><td> 0.50</td>

<td></td><td> 29</td><td> 10</td>

<td></td><td> 30</td><td> 100</td>

/ neurite outgrowth, nM

Sciatic Nerve Axotomy

Six-week old male Sprague-Dawley rats were anesthetized, and the sciatic nerve exposed and crushed, at the level of the hip, by forceps. Test compounds or vehicle were administered subcutaneously just prior to the lesion and daily for the following 18 5 days. Sections of the sciatic nerve were stained with

Holmes silver stain .to quantify the number of axons, and Luxol fast blue to quantify the level of myelination. Eighteen days after lesion, there was a significant decrease in the number of axons (50% decrease as compared to non-lesioned control) and degree of myelination (90% decrease as compared to nonlesioned control) in animal treated with vehicle.

Administration of Example 1 (30 mg/kg s.c.), just prior to the lesion and daily for 18 days following the 15 lesion, resulted in significant regeneration of both axon number (5% decrease as compared to non-lesioned control) and the degree of myelination (50% decrease as compared to control) as compared to vehicle treated animals. The significant efficacy of Example 1 is consistent with its potent activity in inhibiting rotamase activity and stimulating neurite outgrowth in chick DRGs. These results are shown in Figure 3. Sham denotes control animals that received vehicle but were not lesioned; Vehicle denotes animals that were lesioned and received only vehicle (i.e., no drug).

Example 1 showed a striking similarity co the sham treated animals, demonstrating the powerful neuroregenerative effects of these compounds in vivo.

Inactive is a compound that is inactive as an FKBP12 inhibitor. Animals treated with this compound resembled the vehicle-treated lesioned animals, consistent with the neuroregenerative results observed with Example 1 5 being directly caused by its inhibition of FKBP12.

Quantitation for these data are shown in Table III.

Table III

<td> • · · • ·</td><td></td><td> Treatment</td><td> Axon Number</td><td> Myelin Level</td>

<td> • · · • · • ·</td><td></td><td></td><td> (% Control)</td><td></td>

<td> • · · · • · ·· •</td><td> 10</td><td> Sham</td><td> 100</td><td> 100</td>

<td> • · · ·</td><td></td><td> Lesion:</td><td></td><td></td>

<td> • · • · ·</td><td></td><td> + Vehicle (s.c.)</td><td> 50</td><td> 10</td>

<td> • · · • ·</td><td></td><td> + Example 1</td><td> 100</td><td> SO</td>

<td> •</td><td></td><td> (30 mg/</td><td></td><td></td>

<td></td><td> 15</td><td> kg s.c.)</td><td></td><td></td>

<td> • · · ·</td><td></td><td> + Inactive</td><td> 25</td><td> 25</td>

<td> • · · • · · ·</td><td></td><td> (3 0 mg/kg s.c.)</td><td></td><td></td>

MPTP Model of Parkinson's Disease in Mice

MPTP lesioning of dopaminergic neurons in mice was used as an animal model of Parkinson's Disease. Four week old male CD1 white mice were dosed i.p. with 3 0 mg/kg of MPTP for 5 days. Example 17(10-40 mg/kg), or vehicle, were administered s.c. along with the MPTP for 5 days, as well as for an additional 5 days following cessation of MPTP treatment. At 18 days following MPTP *

treatment, the animals were sacrificed and the striata were dissected and homogenized. Binding of [3H]CFT, a radioligand for the dopamine transporter, to the stiatal membranes was done to quantitate the level of 30 the dopamine transporter (DAT) following lesion and drug treatment. Immunostaining was performed on saggital and coronal brain sections using anti-tyrosine hydoxylase Ig to quantitate survival and recovery of dopaminergic neurons . In animals treated with MPTP and vehicle, a substantial loss of functional dopaminergic terminals was observed as compared to non-lesioned animals. Lesioned animals receiving Example 17 showed a nearly quantitative recovery of ΤΉ-stained dopaminergic neurons.

Figures 4 and 5 show the quantitation in DAT levels, whereas figures 6-8 are photomicrographs showing the regenerative effects of Example 17 in this model. Figure 4 demonstrates the significant recovery in functional dopaminergic terminals, as assayed by [3H] -CFT binding, relative to animals receiving MPTP but not the Guilford compounds. Figure 5 gives this data in bar graph form. It is shown that animals receiving 40 mg/kg of Example 17 in addition to MPTP manifested a greater than 90% recovery of [3H] -CFT binding. As shown in Figures 6-8, immunostaining for tyrosine hydroxylase (a marker of viable dopaminergic neurons) in the striatum, the nigra, and the medial forebrain bundle, shows a clear and marked recovery of functional neurons in animals that received Example 17, as compared to animals that received lesioning agent but no drug (MPTP/Vehicle) .

The following examples are illustrative of preferred embodiments of the invention and are not to be construed as limiting the invention thereto. All preferred embodiments of.the invention and are not to be construed as limiting the invention thereto. AH polymer molecular weights are mean average molecular weights. All percentages are based on the percent by weight of the final delivery system or formulation prepared unless otherwise indicated and all totals equal 100% by weight.

EXAMPLES

The inventive compounds may be prepared by a variety of synthetic sequences that utilize established chemical transformations. The general pathway to the present compounds is described in Scheme 1. Nglyoxylproline derivatives may be prepared by reacting L-proline methyl ester with methyl oxalyl chloride as shown in Scheme I. The resulting oxamates may be reacted with a variety of carbon nucleophiles to obtain intermediates compounds. These intermediates are then reacted with a variety of alcohols, amides, or protected amino acid residues to obtain the propyl esters and amides of the invention.

Scheme I

<img file="AU742575B2_D0050.tif" />

<img file="AU742575B2_D0051.tif" />

EXAMPLE 1

Synthesis of 3-phenyl-1-propyl (2S)-l-(3,3-dimethyl-

1,2-dioxopentyl)-2-pyrrolidinecarboxylate (Example 1).

Synthesis of methyl (2S)-1-(1,2-dioxo-2methoxyethyl) -2 -pyrrolidinecarboxylate.

A solution of L-proline methyl ester hydrochloride (3.08 g; 18.60 mmol) in dry methylene chloride was cooled to 0°C and treated with triethylamine (3.92 g;

38.74 mmol; 2.1 eq). After stirring the formed slurry under a nitrogen atmosphere for 15 min, a solution of methyl oxalyl chloride (3.20 g; 26.12 mmol) in methylene chloride (45 mL) was added dropwise. The resulting mixture was stirred at 0°C for 1.5 hr. Aft®*^- filtering to remove solids, the organic phase was washed with water, dried over MgSO, and concentrated.

The crude residue was purified on a silica gel column, eluting with 50% ethyl acetate in hexane, to obtain 3.52 g (88%) of the product as a reddish oil. Mixture of cis-trans amide rotamers; data for trans rotamer given. ^XH NMR (CDC1₃) : d .1.93 (dm, 2H) ; 2.17 (m, 2H) ; 3.62 (m, 2H); 3.71 (s, 3H); 3.79, 3.84 ( s, 3H total); 4.86 (dd, 1H, J = 8.4, 3.3).

Synthesis of methyl (2S)-1-(l,2-dioxo-3,3dimethylpentyl) - 2 -pyrrol idinecarboxylate.

A solution of methyl (2S)-1-(1,2-dioxo-2methoxyethyl)-2-pyrrolidinecarboxylate (2.35 g; 10.90 mmol) in 30 mL of tetrahydrofuran (THF) was cooled to -78°C and treated with 14.2 mL of a l;0 M solution of 1,1-dimethylpropylmagnesium chloride in THF. After stirring the resulting homogeneous mixture at -78°C for three hours, the mixture was poured into saturated ammonium chloride (100 mL) and extracted into ethyl acetate. The organic phase was washed with water, dried, and concentrated, and the crude material obtained upon removal of the solvent was purified on a silica gel column, eluting with 25% ethyl acetate in' hexane, to obtain 2.10 g (75%) of the oxamate as a colorless oil. ^lH NMR (CDC1₃) : d 0.88 (t, 3H) ; Γ.22, 1.26 (s, 3H each); 1.75 (dm, 2H) ; 1.87-2.10 (m, 3H) ;

2.23 (m, 1H); 3.54 (m, 2H); 3.76 (s, 3H); 4.52 (dm, 1H, J = 8.4, 3.4).

Synthesis of (2S)-1-(1,2-dioxo-3,3dimethylpentyl)-2-pyrrolidinecarboxylic acid.

A mixture of methyl (2S)-1-(1,2-dioxo-3,3dimethylpentyl) -2-pyrrolidinecarboxylate (2.10 g,· 8.23 mmol), 1 N LiOH (15 mL), and methanol (50 mL) was stirred at 0°C for 3 0 min and at room temperature overnight. The mixture was acidified to pH 1 with 1 N HC1, diluted with water, and extracted into 100 mL of methylene chloride. The organic extract was washed with ’ brine and concentrated to deliver 1.73 g (87%) of snowwhite solid which did not require further purification.

^lH NMR (CDC1₃) : d 0.87 (t, 3H) ; 1.22, 1.25 (s, 3H each); 1.77 (dm, 2H) ; 2.02 (m, 2H); 2.17 (m, 1H); 2.25 (m, 1H) ; 3.53 (dd, 2H, J = 10.4,- 7.3); 4.55 (dd, 1H, J =8.6,4.1).

Synthesis of 3-phenyl-1-propyl (2S)-l-(3,315 dimethyl-1,2-dioxopentyl)-2-pyrrolidinecarboxylate (Example 1). A mixture of (2S)-1-(1,2-dioxo-3,3dimethylpentyl)-2-pyrrolidine-carboxylic acid (600 mg; 2.49 mmol), 3-phenyl-1-propanol (508 mg; 3.73 mmol), dicyclohexylcarbodiimide (822 mg; 3.98 mmol), camphorsulphonic acid (19Ό mg; 0.8 mmol) and 4dimethylaminopyridine (100 mg; 0.8 mmol) in methylene chloride (20 mL) was stirred overnight under a nitrogen atmosphere. The reaction mixture was filtered through Celite to remove solids and concentrated in vacuo, and the crude material was purified on a flash column (25% ethyl acetate in hexane) to obtain 720 mg (80%) of

Example 1 as a colorless oil. ^lH NMR (CDClj) : d 0.84 (t, 3H); 1.19 (s, 3H); 1.23 (s, 3H); 1.70 (dm, 2H);

1.98 (m, 5H); 2.22 (m, 1H); 2.64 (m, 2H); 3.47 (m, 2H);

4.14 (m, 2H); 4.51 (d, 1H); 7.16 (m, 3H); 7.26 (m, 2H).

The method of Example 1 was utilized to prepare the following illustrative examples:

Example 2: 3-phenyl-1-prop-2-(E)-enyl (2S)-1-(3,3dimethyl-1,2-dioxopentyl)-2-pyrrolidinecarboxylate, 80%, ^XH NMR (360 Mhz, CDC1₃) : d 0.86 (t, 3H) ; 1.21 (s, 3H); 1.25 (s, 3H); 1.54-2.10 (m, 5H) ; 2.10-2.37 (m, 1H); 3.52-3.55 (m, 2H); 4.56 (dd, 1H, J= 3.8, 8.9);

4.7Θ-4.83 (m, 2H); 6.27 (m, 1H); 6.67 (dd, 1H, J =

15.9) ; 7.13-7:50 (m, 5H) ..

Example 3: 3-(3,4,5-trimethoxyphenyl)-1-propyl (2S)-ΙΟ ,3-dimethy1-1,2-dioxopentyl)-2-pyrrolidine-

<td> • ·</td><td colspan="2"> carboxylate.</td><td colspan="3"> 61%, ^XH NMR (CDC1₃) :</td><td> d 0</td><td> .84</td><td> (t,</td><td> 3H)</td><td> ; 1.</td><td> .15</td>

<td> • · 1 · · · • · · •</td><td> 15 (s, 3H) ;</td><td> 1.24</td><td> (s, 3H);</td><td> 1.71</td><td> (dm,</td><td> 2H)</td><td> ; 1.</td><td> 98</td><td> (m,</td><td> 5H) ;</td><td></td>

<td> ···</td><td> 2.24 (m,</td><td> 1H) ;</td><td> 2.63 (m,</td><td> 2H) ;</td><td> 3.51</td><td> (t,</td><td> 2H)</td><td> ; 3</td><td> .79</td><td> (s,</td><td> 3H) ;</td>

<td> ♦ · • * • ·</td><td> 3.83 (s,</td><td> 3H) ;</td><td> 4.14 (m,</td><td> 2H) ;</td><td> 4.52</td><td> (m,</td><td> 1H)</td><td> ; 6</td><td> .36</td><td> (s,</td><td> 2H) .</td>

Example 4: 3-(3,4,5-trimethoxyphenyl)-l-prop-2-(E)-enyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-2-pyrrolidine carboxylate, 66%, Ή NMR (CDClj) : d 0.85 (t, 3H) ; 1-22 (s, 3H); 1.25 (s, 3H); 1.50-2.11 (m, 5H); 2.11-2.40 (m, 1H) ; 3.55 (m, 2H) ; 3.85 (s, 3H) ; 3.88 (s, 6H) ; 4.56 (dd, 1H); 4.81 (m, 2H); 6.22 (m, 1H) ; 6.58 (d, 1H, J “ 16); 6.63 (s, 2H).

Example 5: 3-(4,5-methylenedioxyphenyl)-1-propyl (2S)-

1-(3,3-dimethyl-l, 2-dioxopentyl) -2-pyrrolidine- carboxylate, 82%, ^XH NMR (360 MHz, CDC1J : d 0.86 (t,3H); 1.22 (s, 3H); 1.25 (s, 3H); 1.60-2.10 (m, 5H) ; 3.36-3.79 (m, 2H); 4.53 (dd, 1H, J = 3.8, 8.6); 4.614.89 (m, 2H); 5.96 (s, 2H); 6.10 (m, 1H); 6.57 (dd, 1H,

J = 6.2, 15.8); 6.75 (d, 1H, J = 8.0); 6.83 (dd, IE, J = 1.3, 8.0) ; 6.93 (s, 1H) .

Example 6: 3-(4,5-methylenedioxyphenyl)-l-prop-2- (E) enyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-2pyrrolidinecarboxylate,82%, ^XH NMR (3 60 MHz, CDClj) : d 10 0.86 (t, 3H); 1.22 (s, 3H); 1.25 (s, 3H); 1.60-2.10 (m,

5H); 2.10-2.39 (m, 1H); 3.36-3.79 (m, 2H); 4.53(dd,

1H, J = 3.8, 8.6); 4.61-4.89 (m, 2H); 5.96 (s, 2H);

6.10 (m, 1H); 6.57 (dd, 1H, J = 6.2, 15.8); 6.75(d,

1H, J « 8.0); 6.83 (dd, 1H, J = 1.3, 8.0); 6.93(s,

151H).

Example 8: 3-cyclohexyl-l-prop-2-(E)-enyl (2S)-1-(3,3dimethyl-1,2-dioxopentyl)-2-pyrrolidinecarboxylate,

92%, ^XH NMR (360 MHz, CDC1₃) : d 0.86 (t, 3H) ; 1.13-1.40 (m + 2 singlets, 9H total); 1.50-1.87 (m, 8H); 1.8720 2.44 (m, 6H); 3.34-3.82 (m, 2H) ; 4.40-4.76 (m, 3H);

5.35-5.60 (m,.lH); 5.60-5.82 (dd, 1H, J =6.5, 16).

Example 9: (IR)-1,3-Diphenyl-1-propyl (2S)-1-(3,3dimethyl-1,2-dioxopentyl)-2-pyrrolidinecarboxylate,

<td> 90%,</td><td>^XH NMR</td><td> (360</td><td> MHz, CDC1₃) :</td><td> : d 0.85</td><td> (t, 3H); 1</td><td> .20 (s,</td>

<td> 25 3H) ;</td><td> 1.23 (s</td><td> , 3H)</td><td> ; 1.49-2.39</td><td> (tn, 7H) ;</td><td> 2.46-2.86</td><td> (m,</td>

<td> 2H) ;</td><td> 3.25-3 .</td><td> 80 (m</td><td> , 2H); 4.42-</td><td> •4.82 (m,</td><td> 1H); 5.82</td><td> (td,</td>

<td> 1H,</td><td> J = 1.8,</td><td> 6.7)</td><td> ; 7.05-7.21</td><td> (m, 3H);</td><td> 7.21-7.46</td><td> (m,</td>

7H) .

fe·

Example 10: 3-phenyl-1-propyl (2S)-1-(l,2-dioxo-2-[2furanyl] )ethyl-2-pyrrolidinecarboxylate, 99%, ^lH NMR (300 MHz, CDClj) : d 1.66-2.41 (m, 6H) ; 2.72 (t, 2H, J =

7.5); 3.75 (m, 2H); 4.21 (m, 2H); 4.61 (m, 1H) ; 6.58 (m, 1H); 7.16-7.29 (m, 5H); 7.73 (m, 2H) .

Example 11: 3-phenyl-1-propyl (2S)-l-(i,2-dioxo-2-[2thienyl] ) ethyl-^2-pyrrolidinecarboxylate, 81%, ^XH NMR (300 MHz, CDC1₃) : d 1.88-2.41 (m, 6H) ; 2.72 (dm, 2H) ;

3.72 (m, 2H) ; 4.05 (m, 1H) ; 4.22 (m, 1H); 4.64 (m, 1H) ;

7.13-7.29 (m, 6H); 7.75 (dm, 1H); 8.05 (m, 1H).

Example 13: 3-phenyl-1-propyl (2S)-1-(1,2-dioxo-2phenyl)ethyl-2-pyrrolidinecarboxylate, 99%, ^XH NMR (300 MHz, CDC1₃) : d 1.97-2.32 (m, 6H) ; 2.74 (t, 2H, J =

7.5); 3.57 (m, 2H) ; 4.24 (m, 2H) ; 4.67 (m, 1H) ; 6.95-

7.28 (m, 5H); 7.51-7.64 (m, 3H); 8.03-8.09 (m, 2H).

Example 14: 3-(2,5-dimethoxyphenyl)-1-propyl (2S)-ΙΟ , 3-dimethyl-l, 2-dioxopentyl) -2-pyrrolidinecarboxylate, 99%, ^XH NMR (300 MHz, CDC1₃) : d 0.Θ7 (t,

<td> • • · · •</td><td> 3H)_;</td><td> 1.22</td><td> (s,</td><td> 3H); 1.26</td><td> Cs,</td><td> 3H) ; 1.69</td><td> (m,</td><td> 2H); 1.96</td><td> (m,</td>

<td></td><td> 20 5H) ;</td><td> 2.24</td><td> (m,</td><td> 1H); 2.68</td><td> (m,</td><td> 2H); 3.55</td><td> (m,</td><td> 2H); 3.75</td><td> (s,</td>

<td></td><td> 3H) ;</td><td> 3.77</td><td> (s,</td><td> 3H) ; 4.17</td><td> (m,</td><td> 2H); 4.53</td><td> (d,</td><td> 1H); 6.72</td><td> (m,</td>

3H) .

Example 15 : 3- (2,5-dimethoxyphenyl) -l-prop-2- (E) -enyl (2S) -1-(3,3-dimethyl-1,2-dioxopentyl) -2-pyrrolidine-

<td colspan="3"> carboxylate,</td><td> 99%,</td><td>^XH NMR</td><td colspan="3"> (300 MHz, CDC1₃) :</td><td> d 0.87. (t,</td>

<td> 3H) ;</td><td> 1.22</td><td> (s,</td><td> 3H)</td><td> ; 1.26</td><td> (s,</td><td> 3H) ; 1.67</td><td> (m,</td><td> 2H); 1.78 (m,</td>

<td> 1H) ;</td><td> 2.07</td><td> (m,</td><td> 2H)</td><td> ; 2.26</td><td> (m,</td><td> 1H) ; 3.52</td><td> (m,</td><td> 2H); 3.78 (s,</td>

<td> 3H) ;</td><td> 3.80</td><td> (s,</td><td> 3H)</td><td> ; 4.54</td><td> (m,</td><td> 1H); 4.81</td><td> (m,</td><td> 2H); 6.29</td>

(dt, 1H, J = 15.9); 6.98 (s, 1H) .

Example 16: 2-(3,4, 5-trimethoxyphenyl)-1-ethyl (2S)-ΙΟ, 3-dimethyl-1,2-dioxopentyl)-2-pyrrolidine-

<td> car</td><td> boxylate,</td><td> 97%,</td><td>^XH NMR (30</td><td colspan="2"> 0 MHz, CDClj) :</td><td> d (</td><td> ).84 (t,</td>

<td> 5 3H)</td><td> ; 1.15 (s,</td><td> 3H)</td><td> ; 1.24 (s,</td><td> 3H)</td><td> ; 1.71 (dm,</td><td> 2H)</td><td> ; 1.98 '</td>

<td> (m,</td><td> 5H); 2.24</td><td> (m,</td><td> 1H); 2.63</td><td> (m,</td><td> 2H) ,· 3.51</td><td> (t,</td><td> 2H); 3.79</td>

<td> (s,</td><td> 3H); 3.83</td><td> (s,</td><td> 3H) ; 4.14</td><td> (m,</td><td> 2H); 4.52</td><td> (m,</td><td> 1H); 6.36</td>

<td> (s,</td><td> 2H) .</td><td></td><td></td><td></td><td></td><td></td><td></td>

Example 17: 3-(3-Pyridyl)-1-propyl (£S)-1-(3,310 dimethyl-1,2-dioxopentyl)-2-pyrrolidinecarboxylate,

<td> • · · · • · • ·</td><td> 80%,</td><td>^XH NMR</td><td> (CDClj,</td><td> 300</td><td> MHz) :</td><td> d 0</td><td> .85</td><td> (t, 3H); 1.23,</td>

<td> • · · • · •</td><td> 1.26</td><td> (s, 3H</td><td> each);</td><td> 1.63</td><td> -1.89</td><td> (m,</td><td> 2H)</td><td> ; 1.90-2.30 (m,</td>

<td> • · « ·</td><td> 4H) ;</td><td> 2.30-2.</td><td> 50 (m,</td><td> 1H) ;</td><td> 2.72</td><td> (t,</td><td> 2H)</td><td> ; 3.53 (m, 2H);</td>

<td> • · • · · * · · · • ·</td><td> 4.19</td><td> (m, 2H)</td><td> ; 4.53</td><td> (m,</td><td> 1H) ; 7</td><td> .22</td><td> (m,</td><td> 1H); 7.53 (dd,</td>

<td> • · ·</td><td> 15 1H);</td><td> 8.45.</td><td></td><td></td><td></td><td></td><td></td><td></td>

Example 18: 3-(2-Pyridyl)-1-propyl (2S)-1-(3,3dimethyl-1,2-dioxopentyl) -2-pyrrolidinecarboxylate,

<td> 88%,</td><td>^XH NMR</td><td> (CDClj,</td><td> 300 MHz) :</td><td> d 0 .</td><td> 84</td><td> (t, 3H)</td><td> ; 1.22,</td>

<td> 1.27</td><td> (S, 3H</td><td> each);</td><td> 1.68-2.32</td><td> (m,</td><td> 8H)</td><td> ; 2.88</td><td> (t, 2H, J</td>

<td> 20 7.5);</td><td> 3.52</td><td> (m, 2H) ,-</td><td> 4.20 (m,</td><td> 2H) ;</td><td> 4 .</td><td> 51 (m,</td><td> 1H); 7.09-</td>

<td> 7.19</td><td colspan="2"> (m, 2H); 7.59</td><td> (m, 1H) ; 8</td><td> .53</td><td> (d,</td><td> 1H, J</td><td> = 4.9).</td>

•Example 19: 3-(4-Pyridyl)-1-propyl (2S)-1-(3,3dimethy1-1,2-dioxopentyl)-2-pyrrolidinecarboxylate,

91%, ’Ή NMR (CDClj, 300 MHz): d 6.92-6.80 (m, 4H) ; 6.28 (m, 1H); 5.25 (d, 1H, J = 5.7); 4.12 (m, 1H); 4.08 (s,

3H); 3.79 (s, 3H); 3.30 (m, 2H); 2.33 (m, 1H); 1.851.22 (tn, 7H)·; 1.25 (s, 3H) ; 1.23 (s, 3H) ; 0.89 (t, 3H,

7.5) .

<img file="AU742575B2_D0052.tif" />

Example 20: 3-phenyl-1-propyl (2S)-1-(2-cyclohexyl-i,2dioxoethyl)-2-pyrrolidinecarboxylate, 91%, ^lH NMR (CDClj, 300 MHZ): d 1.09-1.33 (m, 5H); 1.62-2.33 (m, 12H); 2.69 )t, 2H, J = 7.5); 3.15 (dm, 1H) ; 3.68 (m,

2H); 4.16 (m, 2H); 4.53, 4.84 (d, 1H total); 7.19 (m,

3H); 7.29 (m, 2H).

Example 21: 3-phenyl-1-propyl (2S)-1-(2-tert-butyl-1,2dioxoethyl)-2-pyrrolidinecarboxylate, 92%, ^XH NMR (CDClj, 300 MHz): d 1.29 (s, 9H); 1.94-2.03 (m, 5H) ;

2.21 (m, 1H); 2.69 (m, 2H); 3.50-3.52 (m, 2H); 4.16 (m, 2H); 4.53 (m, 1H); 7.19 (m, 3H); 7.30 (m, 2H).

Example 22: 3-phenyl-1-propyl (2S)-1-(2-cyclohexylethyl-1,2-dioxoethyl)-2-pyrrolidinecarboxylate, 97%, *H

<td> NMR (CDClj, 300 MHz): d 0.88 (m, 2H) ; 1.16 (m, 4H) ;</td>

<td> 15 1.43-1.51 (m, 2H); 1.67 (m, 5H) ; 1.94-2.01 (m, 6H);</td>

<td> 2.66-2.87 (m, 4H); 3.62-3.77 (m, 2H); 4.15 (m, 2H);</td>

<td> 4.86 (m, 1H) ; 7.17-7.32 (m, 5H) .</td>

Example 23: 3-(3-pyridyl)-1-propyl (2S)-1-(2-cyclohexylethyl-1,2-dioxoethyl)-2-pyrrolidinecarboxylate,

<td> 20 70%,</td><td>^XH NMR</td><td> (CDClj,</td><td> 300</td><td> MHz)</td><td> : d 0.87</td><td> (m, 2H) ; 1-.16</td><td> (m,</td>

<td> 4H) ;</td><td> 1.49 (m,</td><td> 2H) ;</td><td> 1.68</td><td> (m,</td><td> 4H); 1.95</td><td> -2.32 (m, 7H);</td><td></td>

<td> 2.71</td><td> (m, 2H) ;</td><td> 2.85</td><td> (m, :</td><td> 2H) ;</td><td> 3.63-3.78</td><td> (m, 2H) ; 4.19</td><td> (m,</td>

<td> 2H) ;</td><td> 5.30 (m,</td><td> 1H) ;</td><td> 7.23</td><td> (m,</td><td> 1H); 7.53</td><td> (tn, 1H) ; 8.46</td><td> (m,</td>

2H) .

Example 24: 3-(3-pyridyl)-1-propyl (2S)-1-(2-tertbutyl -1,2-dioxoethyl)-2-pyrrolidinecarboxylate, 83%, ^XH

NMR (CDClj, 300 MHz): d 1.29 (s, 9H) ; 1.95-2.04 (m,

5H) ; 2.31 (m, 1H) ; 2.72 (t, 2H, J = 7.5); 3.52 (m, 2H) ;

4.18 (m, 2H); 4.52 (m, 1H); 7.19-7.25 (m, 1H); 7.53 (m, 1H) ; 8.46 (m, 2H) .

Example 25: 3,3-diphenyl-1-propyl (2S)-1-(3,3-dimethyl-

1,2-dioxopentyl)-2-pyrrolidinecarboxylate, 99%, ^lH NMR (CDClj, 300 MHz): d 0.85 (t, 3H) ; 1.21, 1.26 (s, 3H each); 1.68-2.04 (m, 5H); 2.31 (m, 1H) ; 2.40 (m, 2H);

3.51 (m, 2H); 4.08 (m, 3H); 4.52 (m, 1H); 7.18-7.31 (m, 10H) . .

Example 26: 3-(3-pyridyl)-1-propyl (2S)-1-(2-cyclo10 hexyl-1,2-dioxoethyl)-2-pyrrolidinecarboxylate, 88%, ^XH

NMR (CDC1₃, 300 MHz): d 1.24-1.28 (m, 5H) ; 1.88-2.35 (m, 11H); 2.72 (t, 2H, J= 7.5); 3.00-3.33 (dm, 1H);

3.69 (m, 2H); 4.19 (m, 2H); 4.55 (m, 1H); 7.20-7.24 (m, 1H) ; 7.53 (m, 1H); 8.47 (m, 2H). *

Example 27: 3-(3-Pyridyl)-1-propyl (2S)-N-([2-thienyl]

<td colspan="2"> glyoxyl)pyrrolidinecarboxylate,</td><td> 49%,</td><td colspan="2">^XH NMR (CD</td><td> Cl,,</td><td> 300</td>

<td> MHz) :</td><td> d 1.81-2.39 (m, 6H); 2.72</td><td> (dm,</td><td> 2H) ;</td><td> 3.73</td><td> (m,</td><td> 2H) ;</td>

<td> 4.21</td><td> (m, 2H) ; 4.95 (m, 1H); 7.19</td><td> (m,</td><td> 2H);</td><td> 7.61</td><td> (m,</td><td> 1H) ;</td>

<td> 7.80</td><td> (d, 1H); 8.04 (d, 1H); 8.46</td><td> (m,</td><td> 2H) .</td><td></td><td></td><td></td>

Example 28: 3,3-Diphenyl-1-propyl (2S) -1-(3,3-dimethyl-

1,2-dioxobutyl)-2-pyrrolidinecarboxylate, 99%, ¹H NMR (CDClj, 300 MHz): d 1.27 (s, 9H) ; 1.96 (m, 2H) ; 2.44 (m, 4H) ; 3.49 (m, 1H) ; 3.64 (tn, 1H) ; 4.08 (m, 4H) ; 4.53 (dd, 1H); 7.24 (m, 10H).

Example 29: 3,3-Diphenyl-1-propyl (2S)-1-cyclohexyl glyoxyl-2-pyrrolidinecarboxylate, 91%, ^lH NMR (CDClj,

300 MHz): d 1.32 (m, 6H); 1.54-2.41 (m, 10H); 3.20 (dm, 1H); 3.69 (m, 2H); 4.12 (m, 4H) ; 4.52 (d, 1H);

7.28 (Hl, 10H) ·

Example 30: 3,3-Diphenyl-1-propyl (2S) -1-(2-thienyl) glyoxyl-2-pyrrolidinecarboxylate, 75%, *H NMR (CDC1₃, 300 MHz): d 2.04 (m, 3H); 2.26 (m, 2H); 2.48 (m, 1H);

3.70 (m, 2H); 3.82-4.18 (m, 3H total); 4.64 (m, 1H) ;

7.25 (m, 11H) ; 7.76 (dd, 1H); 8.03 (m, 1H) .

The requisite substituted alcohols may be prepared by a number of methods known to those skilled in the art of organic synthesis.. As described in Scheme II, alkyl or aryl aldehydes may be homologated to phenyl propanols by reaction with methyl (triphenylphosphoranylidene)acetate to provide a variety of trans-cinnamates; these latter may be reduced to the saturated alcohols by reaction with excess lithium aluminum hydride, or sequentially by reduction of the double bond by catalytic hydrogenation and reduction of the saturated ester by appropriate reducing agents. Alternatively, the trans-cinnamates may be reduced to (E)-allylic alcohols by the use of i

diisobutylaluminum hydride.

R-CH0

PhgP-O-COOCHg

<img file="AU742575B2_D0053.tif" />

Lithium aluminum hydride

---------►

<img file="AU742575B2_D0054.tif" />

<img file="AU742575B2_D0055.tif" />

<img file="AU742575B2_D0056.tif" />

<img file="AU742575B2_D0057.tif" />

Pd/C

Λ

Lithium aluminum hydride or □isobutylaluminum hydride

Scheme II

Longer chain alcohols may be prepared by homologation of benzylic and higher aldehydes. Alternatively, these aldehydes may be prepared by conversion of the corresponding phenylacetic and higher acids, and phenethyl and higher alcohols.

General procedure for the synthesis of acrylic esters, exemplified for methyl (3,3,5-trimethoxy)trans-cinnamate:

A solution of 3,4,5-trimethoxybenzaldehyde (5.0 g;

25.48 mmol) and methyl (triphenylphosphoranylidene)acetate (10.0 g; 29.91 mmol) in tetrahydrofuran (250 mL) was refluxed overnight. After cooling, the reaction mixture was diluted with.200 mL of ethyl acetate and washed with 2 x 200 mL of water, dried, and concentrated in vacuo. The crude residue was chromatographed on a silica gel column, eluting with 25% ethyl acetate in hexane, to obtain 5.63 g (88%) of the cinnamate as a white crystalline solid, ¹H NMR (300 Mhz; CDClj) : d 3.78 (s, 3H) ; 3.85 (s, 6H) ; 6.32 (d,

1H,,J - 16); 6.72 (s, 2H); 7.59 (d, 1H, J - 16).

General procedure for the synthesis of saturated alcohols from acrylic esters. Exemplified for (3,4,5trimethoxy) phenylpropanol.

A solution of methyl (3,3,5-trimethoxy)-trans25 cinnamate (1.81 g; 7.17 mmol).in tetrahydrofuran (30 mL) was added in a dropwise manner to a solution of lithium aluminum hydride (14 mmol) in THF (35 mL), with stirring and under an argon atmosphere. After the fry·’ addition was complete, the mixture was heated to 75°c for 4 hours. After cooling, it was quenched by the careful addition of 15 mL of 2N NaOH followed by so mL of water. The resulting mixture was filtered through -5 Celite to remove solids, and the filter cake was washed with ethyl acetate. The combined organic fractions were washed with water, dried, concentrated in vacuo, and purified on a silica gel column, eluting with ethyl acetate to obtain 0.86 g (53¾) of the alcohol as a *··· • · •· • ·· • · · a· *

clear oil, ^XH

1.87 (m, 2H);

(S, 3H); 3.83

NMR (300

2.61 (t, (s, 6H);

Mhz; CDC1₃) : d 1.23 (br, 1H) ;

2H, J = 7.1); 3.66 (t, 2H); 3.80

6.40 (s, 2H).

• · ·· · • 9 · · • · • · ·

General procedure for the synthesis of transallylic alcohols from acrylic esters. Exemplified for (3,4,5-trimethoxy)phenylprop-2-(E)-enol.

A solution of methyl (3,3,5-trimethoxy)-transcinnamate (1.35 g; 5.35 mmol) in toluene (25 mL) was cooled to -10°C and treated with a solution of diisobutylaluminum hydride in toluene (11.25 mL of a

1.0 M solution; 11.25 mmol).

The reaction mixture was stirred for 3 hrs at

0^eC and then quenched with 3 mL of methanol followed by

N HCI until the pH was 1. The reaction mixture was extracted into ethyl acetate' and the organic phase was washed with water, dried and concentrated. Purification on a silica gel column eluting with 25¾ ethyl acetate in hexane furnished 0.96 g (80¾) of a thick oil, ^XH NMR (360 Mhz; CDClj) : d

3.85 (s, 3H); 3.87 (s, 6H) ; 4.32 (d, 2H, J = 5.6); 6.29 (dt, 1H, J = 15.8, 5.7), 6.54 (d, 1H, J = 15.8); 6.61 (s, 2H).

The invention being thus described, it will be obvious that the same may be varied in many ways. Such 5 variations are not to be regarded as a departure from the spirit and scope of the invention and all such modification are intended to be included within the scope of the following claims.

Where the terms “comprise”, “comprises”, “comprised” or “comprising” are used in this specification, they are to be interpreted as specifying the presence of the stated features, integers, steps or components referred to, but not to preclude the presence or addition of one or more other feature, integer, step, component or group thereof.

The present application is a divisional application of Australian Application No. 61062/96. The specification of which as published prior to acceptance is incorporated herein by reference.