Substituted n-benzyl-indol-3-yl glyoxylic acid derivatives having an anti-tumoral effect

ES 2 215 768 T3

DESCRIPTION

Substituted N-benzyl-indol-3-yl-glyoxylic acid derivatives with antitumor effect.

Indole-3-glyoxylamides have multiple applications as pharmacodynamic compounds and as synthetic links in pharmaceutical chemistry.

In the patent application Neth. Appl. 6502481 describes compounds that have an anti-inflammatory and antipyretic action profile, and analgesic activity.

In the British application GB-PS 1 028 812 derivatives of indole-3-glyoxylic acid and its amides are mentioned as effective analgesic, anticonvulsant and ye-adrenergic compounds.

G. Domschke et al. (Ber. 94, 2353 (1961)) describes 3-indolyl-glyoxylamides that are not pharmacologically characterized.

E. Walton reports in J. Med. Chem 11, 1252 (1968) on derivatives of indolyl-3-glyoxylic acid that act as inhibitors of glycerophosphate dehydrogenase and lactate dehydrogenase.

In the European patent specification EP 675 110 1H-indole-3-glyoxylic acid amides are described that are outlined as sPLA2 inhibitors and that are used in the treatment of septic shock, in pancreatitis, in the treatment of allergic rhinitis. and in rheumatic arthritis.

Furthermore, in the German patent application under the file number 198 14 838.0 it was already proposed to use the compounds as antitumor products according to DE-OS 196 36 150 A1.

Indole-3-glyoxylic acid derivatives that can be used for the treatment of tumor conditions are disclosed in patent specification WO 99/51224. Compounds are described in which the indole-nitrogen can be substituted with arylalkyl groups, but in which the aryl linkage does not have nitrogen substitution.

E. Polymeropoulus et al. reports in "A peptidic binding site model for PDE 4 inhibitors", Quant. Struct.-Act. Relat., Volume 18, n ° 6, 1999, pages 543-7, XP00103O741, on a new model of peptide bonding of derivatives of 5-methoxy- and 5-hydroxy-indol-3-ylo-glycoxylic acid with inhibitory activity of the PDE-4.

The purpose of the present invention is to make available new compounds of the indole-3-ylglycoxylic acid series of the general formula 1 which have a good antitumor active effect and which can be used to produce antitumor agents;

<img file="ES2215768T3_D0001.tif" />

where the residues R, R1, R2, R3, R4 and Z have the following meaning:

R = nitro, amino, mono- or di-(C1-C6) alkyl-amino, mono- or di-cyclo (C1-C6) -amino, acyl (C1-C6) -amino, phenyl-C1-C6 alkyl ) -amino, aroylamino, heteroaroylamino, (C1-C6) alkyl-sulfonamido, arylsufonamido, maleinimido, succinimido, phthalimido, benzyloxycarbonylamino (Z-amino), tert-butoxycarbonylamino (BOC-amino), 9-fluorenylmethoxycarbonylamino (F-fluorenylmethoxycarbonylamino) , triphenylmethylamino (Tr-amino), 2- (4'-pyridyl) -ethoxycarbonylamino (Pyoc-amino), diphenylmethylsilyl-amino (DPMS-amino), where the paraR moieties can be optionally substituted on the C 2, 3 and 4 atoms of the phenyl ring,

R can also mean, for the case that R1 = hydrogen, the methyl or phenylmethyl group, as well as the benzyloxycarbonyl radical (Z radical), the tert-butoxycarbonyl radical (BOC radical) and the acetyl group, the following radicals:

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-NH-CH2-COOH; -NH-CH (CH3) -COOH;

(CH3) 2CH-CH2-CH2-CH (NH) -COOH; H3C-CH2-CH (CH3) -CH (NH) -COOH;

HOH2C-CH (NH) -COOH; phenyl-CH2-CH (NH) -COOH; (4-imidazoyl) -CH2-CH (NH) -COOH;

HN = C (NH2) -NH- (CH2) 3-CH (NH) -COOH; H2N- (CH2) 4 -CH (NH) -COOH;

H2N-CO-CH2-CH (NH) -COOH; HOOC- (CH2) 2-CH (NH) -COOH

R1 = hydrogen, alkyl- (C1-C6), where the alkyl group can be substituted, one or more times, with the phenyl ring and this phenyl ring, in turn, can be substituted one or more times with halogen, alkyl - (C1 -C6), cycloalkyl- (C3 -C7), with carboxylic groups, with carboxylic groups esterified with C1-C6 alkanols, trifluoromethyl groups, hydroxyl groups, methoxy groups, ethoxy groups, benzyloxy groups, as well as with a benzyl group substituted on the phenyl part, one or more times, with (C1-C6) alkyl groups, halogen atoms or trifluoromethyl groups,

R1 also represents the benzyloxycarbonyl group (group Z) and represents the tertiary -butoxycarbonyl residue (Boc residue) and, furthermore, represents the acetyl group,

R2 can mean the phenyl ring, which is substituted, one or more times, with (C1-C6) alkyl, (C1-C6) alkoxy, cyano, halogen, trifluoromethyl, hydroxy, benzyloxy, nitro, amino, (C1-C6) alkyl ) -amino, (C1-C6) alkoxycarbonyl-amino and with the carboxyl group or with the carboxyl group esterified with C1-C6 alkanols, or a pyridine structure of the formula 2

<img file="ES2215768T3_D0002.tif" />

and its oxide N, wherein the pyridine structure is optionally combined with the 2, 3 and 4 carbon atoms of the ring and may be substituted with the R5 and R6 substituents. The residues R5 and R6 can be the same or different and can have the meaning of alkyl (C1-C6), as well as the meaning of cycloalkyl (C3-C7), alkoxy (C1-C6), nitro, amino, hydroxy, halogen and trifluoromethyl and, in addition, represent the ethoxycarbonylamino residue, as well as the carboxyalkyloxy group, in which the alkyl group can have 1-4 carbon atoms,

R2 can also be a 2- or 4-pyrimidinyl heterocycle, heterocycle, where the 2-pyrimidinyl ring can be substituted, one or more times, with the methyl group and, in addition, the 2-, 3- structure , 4-, 5-, 6-, 7- and 8-quinolyl substituted with (C1-C6) alkyl, halogen, the nitro group, the amino group and the (C1-C6) -amino alkyl radical, represents a group 2 -, 3- and 4-quinolylmethyl, wherein the ring carbons of the pyridylmethyl moiety of the quinolyl group and of the quinolylmethyl moiety may be substituted with (C1-C6) alkyl, (C1-C6) alkoxy, nitro, amino and (C1-C6) alkoxycarbonylamino,

R2 can furthermore, in the case that R1 represents hydrogen, the methyl or benzyl group, as well as the benzyloxycarbonyl radical (Z radical), the tert-butoxycarbonyl radical (BOC radical) and the acetyl group, mean the following radicals:

-CH2COOH; -CH (CH3) -COOH: (CH3) 2CH- (CH2) 2-CH (COOH) -; H3C-H2C-CH (CH3) -CH (COOH) -; HO-H2C-CH (COOH) -; phenyl-CH2-CH (COOH) -; (4-imidazolyl) -CH2-CH (COOH) -; HN = C (NH2) -NH- (CH2) 3-CH (COOH) -; H2N- (CH2) 4 -CH (COOH) -; H2 N-CO-CH2-CH (COOH) -; HOOC- (CH2) 2-CH (COOH) -;

R2 can also be, for the case that R1 means hydrogen, the Z group, the BOC residue, the acetyl group or the benzyl group, the acid residue of a natural or artificial amino acid, for example it can represent the α-glycyl residue, α-sarcosyl, α-alanyl, α-leucyl, α-iso-leucyl, α-seryl, α-phenylalanyl, α-histidyl, α-prolyl, α-arginyl, α-lysyl, αasparagyl and α-glutamyl, where the amino groups of the respective amino acids can be present unprotected or protected. As a protection group for the amino function, the carbobenzoxy radical (Z radical) and the tert-butoxycarbonyl radical (BOC radical) can be considered, as well as the acetyl group. In the case of the asparagyl and glutamyl moiety

ES 2 215 768 T3 claimed for R2, the second, uncombined carboxyl group occurs as a free carboxyl group or in the form of a carboxyl group esterified with C1-C6 alkanols, for example as methyl, ethyl or tert-butyl ester. Furthermore, R2 can mean the allylaminocarbonyl-2-methyl-prop-1-yl group. R1 and R2 can also form, together with the nitrogen atom to which they are attached, a piperazine ring of formula 3 or a homopiperazine ring, provided that R2 represents an aminoalkylene group, in which

Formula 3

R7 represents an alkyl radical, it means a phenyl ring that can be substituted, one or more times, with alkyl (C1-C6), alkoxy (C1-C6), halogen, the nitro group, the amino function and with the group -alkyl (C1-C6) -amino. Furthermore, R7 signifies the benzhydryl group and the bis-p-fluorobenzhydryl group.

R3 and R4 may be the same or different and are hydrogen, (C1-C6) alkyl, (C3-C7) cycloalkyl, (C1-C6) alkanoyl, halogen and benzyloxy. Furthermore, R3 and R4 can mean the nitro group, the amino group, the monoo di-alkyl (C1-C4) -substituted amino group and the alkoxy (C1-C6) -carbonylamino function, or the (C1-C6) alkoxy function. -carbonylaminoalkyl- (C1-C6).

Z represents O and S.

Under the name of the alkyl, alkanol, alkoxy or alkylamino group, for the radicals R, R1, R2, R3, R4, R5, R6 and R7 it is generally understood that alkyl groups are both "straight chain" and also " branched ", where" straight chain alkyl groups "can mean, for example, moieties such as methyl, ethyl, n-propyl, n-butyl, n-pentyl or n-hexyl, and" branched alkyl groups "designate, for For example, moieties such as isopropyl or tert-butyl. By "cycloalkyl" is meant moieties such as, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl. The designation "halogen" represents fluorine, chlorine, bromine or iodine. The designation "alkoxy group" represents moieties such as, for example, methoxy, ethoxy, propoxy, butoxy, isopropoxy, isobutoxy or pentoxy. The term acyl for acylamino radicals is understood to be the formyl, acetyl, propionyl, butyryl, valeryl and isovaleryl groups. The aroyl designation of the aroylamino groups represents benzoyl, naphthoyl, toluoyl, phthaloyl, and the heteroaroyl grouping of heteroaroylamino moieties represents nicotinoyl, isonicotinoyl, tenoyl and furoyl. By the aryl designation of the arylsulfonamido group is meant phenyl, tolyl and naphthyl.

The compounds can also be used as acid addition salts, for example as salts of mineral acids such as, for example, hydrochloric acid, sulfuric acid, phosphoric acid, salts of organic acids such as, for example, acetic acid, lactic acid, malonic acid, maleinic acid, fumaric acid, gluconic acid, glucuronic acid, citric acid, ascorbic acid, embonic acid, methanesulfonic acid, trifluoroacetic acid, succinic acid, 2-hydroxy-ethanesulfonic acid, nicotinic acid and p-toluenesulfonic acid.

Both the compounds of formula 1 and their salts are biologically active. The compounds of formula 1 can be administered in free form or as salts with physiologically compatible acids.

The application can be carried out orally, parenterally, intravenously, transdermally or by inhalation.

Furthermore, the invention relates to pharmaceutical preparations containing at least one of the compounds of formula 1 or their salts with physiologically compatible inorganic or organic acids and, optionally, pharmaceutically applicable excipients and / or diluents or adjuvants.

Suitable forms of application are, for example, tablets, dragees, capsules, solutions for infusion or ampoules, suppositories, plasters, powdered preparations usable for inhalation, suspensions, creams and ointments.

The processes for producing the compounds according to the invention are described in the following reaction schemes 1 and 2 (steps 1-3), as well as in the general prescriptions. All compounds can be prepared as described or analogously:

The compounds of the general formula 1 with Z = O, R = NO2 and NH2 and R2 = aryl, aralkyl and heteroaryl can be obtained according to the following scheme 1:

ES 2 215 768 T3

Scheme 1

1 * stage

<img file="ES2215768T3_D0003.tif" />

1^to stage

The indole derivative, which can be unsubstituted or substituted in a single or multiple way in C-2 or in the phenyl structure, is dissolved in a protic, aprotic bipolar or nonpolar organic solvent such as, for example, isopropanol, tetrahydrofuran, dimethylsulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dioxane, toluene or methylene chloride, and it is added dropwise to a suspension of a molar base or used in excess, prepared in a three-neck flask under an N2 atmosphere such as sodium hydride, powdered potassium hydroxide, potassium tert-butylate, dimethylaminopyridine or sodium amide in a suitable solvent. Then, for example, the desired alkyl, aralkyl or heteroaralkyl halide is added, optionally with the addition of a catalyst such as, for example, copper, and it is allowed to react for some time, for example for 30 minutes to 12 hours and the mixture is maintained. the temperature within a range of 0 ° C to 120 ° C, preferably between 30 ° C and 80 ° C, especially between 50 ° C and 65 ° C. After the end of the reaction, the reaction mixture is introduced into water, the solution is extracted, for example, with diethyl ether, dichloromethane, chloroform, methyl-tert-butyl ether or tetrahydrofuran, and the organic phase obtained in each case is dried with anhydrous sodium sulfate. The organic phase is concentrated in vacuo, the remaining residue is crystallized by mixing in a mortar or the oily residue is cleaned by recrystallization, distillation or column or flash chromatography on silica gel or aluminum oxide. The eluent used is, for example, a mixture of dichloromethane and diethyl ether in the ratio 8: 2 (vol / vol), or a mixture of dichloromethane and ethanol in the ratio 9: 1 (vol / vol).

2nd stage

The N-substituted indole obtained according to the above-mentioned prescription of the 1st step is dissolved under a nitrogen atmosphere in an aprotic or apolar organic solvent, for example diethyl ether, methyl-tert-butyl ether, tetrahydrofuran, dioxane, toluene, xylene, chloride of methylene or chloroform and added to a solution, prepared under a nitrogen atmosphere, of a single molar amount to 60 percent excess of oxalyl chloride in an aprotic or apolar solvent, for example in diethyl ether, methyl tert-butyl ether, tetrahydrofuran, dioxane, toluene, xylene or chloride

ES 2 215 768 T3 of methylene, where the temperature is kept between -5 ° C and 20 ° C. The reaction solution is then heated to a temperature between 10 ° C and 130 ° C, preferably between 20 ° C and 80 ° C, especially between 30 ° C and 50 ° C, for a period of 30 minutes to 5 hours. and then the solvent is distilled off. The remaining residue of the "indolyl-3-glyoxylic acid chloride" thus obtained is dissolved in an aprotic solvent, for example tetrahydrofuran, dioxane, diethyl ether or toluene, or else in a bipolar aprotic solvent such as, for example, dimethylformamide, dimethylacetamide or dimethylsulfoxide, it is cooled to a temperature between 10 ° C and -15 ° C, preferably between -5 ° C and 0 ° C, and in the presence of an acid scavenger it is mixed with a solution of the primary or secondary amine in a diluent. As diluents, the solvents previously used to dissolve indolyl-3-glyoxylic acid chloride can be used. As acid scavengers, triethylamine, pyridine, dimethylaminopyridine, basic ion exchangers, sodium carbonate, potassium carbonate, powdered potassium hydroxide, as well as primary or secondary amine used for the reaction can be used. The reaction occurs at a temperature of 0 ° C to 120 ° C, preferably at 20 ° -80 ° C, especially between 40 ° C and 60 ° C. After a reaction time of 1-3 hours and standing for 24 hours at room temperature, the hydrochloride is filtered from the acid scavenger, the filtrate is concentrated in vacuo and the residue is recrystallized from an organic solvent or purified by chromatography. in column through silica gel or aluminum oxide. The eluent used is, for example, a mixture of dichloromethane and ethanol (95: 5, vol / vol).

3^to stage

The N-nitrobenzyl substituted “indoleglyoxylic acid amide”, obtained according to the previous prescription (2nd step), is dissolved in a protic solvent such as, for example, methanol, ethanol, propanol, isopropanol or butanol, or in an apolar solvent such as , for example tetrahydrofuran, dioxane or glycol dimethyl ether, or in a dipolar aprotic solvent, for example dimethylsulfoxide, dimethylformamide, dimethylacetamide or N-methylpyrrolidone, and the solution is mixed under nitrogen atmosphere and stirring with a hydrating catalyst, for example Raney nickel, palladium / carbon or platinum. Hydrogen is added to the suspension under moderate shaking with a gaseous pressure of 1-15 bar, preferably 2-10 bar, especially at 4-6 bar, and the temperature is increased to approximately 20 ° -80 ° C, preferably 30 ° -60 ° C, especially at 45 ° -55 ° C. Eventually, after approx. 1 Once again, a quantity of catalyst is added and the hydration is continued. After a reaction period of 4-10 hours, the hydration was complete. The catalyst is filtered under a nitrogen atmosphere, the solvent is concentrated in vacuo to dryness and the colorless residue is dried to yellowish in vacuo at 40 ° C.

Execution examples

According to this general prescription for steps 1-3, which are based on Synthesis Scheme 1, the following compounds were synthesized, listed in the summary below, with an indication of the corresponding chemical name:

Example 1

N- (pyridin-4-yl) - [1- (4-aminobenzyl) -indol-3-yl] glycoxylic acid amide (D-68838)

1st stage

1- (4-nitrobenzyl) -indole

A mixture of 5.28 g of sodium hydride (0.22 mol, suspension in mineral oil) in 200 ml of dimethylsulfoxide is combined with a solution of 23.4 g (0.2 mol) of indole in 100 ml of dimethylsulfoxide. It is heated for 1 hour at 65 ° C, then it is allowed to cool and then 37.7 g (0.22 mol) of 4-nitrobenzyl chloride are added dropwise. The solution is heated to 60 ° C, stored for 14 hours at room temperature and then poured into 700 ml of water with stirring. It is extracted in portions with a total of 300 ml of methylene chloride, the organic phase is dried over anhydrous sodium sulfate, filtered and the filtrate is concentrated in vacuo. The residue is purified through a silica gel column (silica gel 60. Firm Merck AG, Darmstadt; eluent methylene chloride / ethanol 9: 1, v / v).

Yield: 43.9 g (87% of theory)

Mass Spectrum: m / e 253 (M + H)

2nd stage

N- (Pyridin-4-yl) - [1- (4-nitrobenzyl) -indol-3-yl] glyoxylic acid amide (D-68836)

A solution of 4.50 ml of oxalyl chloride is mixed in 50 ml of ether at 0 ° C and added under a nitrogen atmosphere dropwise to a solution of 10.09 g (0.04 mol) of 1- ( 4-nitrobenzyl) -indole in 50 ml of ether. Heat for 2 hours at reflux temperature, then the solvent is evaporated off. 100 ml of tetrahydrofuran are added to the residue, it is cooled to -5 ° C and a solution of 9.32 g (0.099 mol) of 4-aminopyridine in 400 ml of tetrahydrofuran is added dropwise. Heat for 3 hours under reflux and allow to stand overnight at room temperature. The 4-aminopyridine hydrochloride is filtered off with suction, the precipitate is washed with tetrahydrofuran, the filtrate is concentrated in vacuo and the residue is recrystallized from acetic ester.

ES 2 215 768 T3

Yield: 13.5 g (84% of theory)

Mass Spectrum: m / e 401 (M + H)

3^to stage

N- (pyridin-4-yl) - [1- (4-aminobenzyl) -indol-3-yl] glyoxylic acid amide (D-68838)

A mixture of 200 mg of Raney nickel in 50 ml of dioxane is combined with a suspension of 320 mg (0.8 mmol) of acid amide N- (pyridin-4-yl) - [1- (4-nitrobenzyl) - indol-3-yl] -glyoxylic in a solvent mixture of 150 ml of dioxane and 20 ml of isopropanol. Hydrogen is introduced into this suspension under shaking with a gaseous pressure of 5 bar and the temperature is kept at 30-35 ° C. After approx. 3 hours, another 400 mg of Raney nickel are added and the hydrogenation is continued under vigorous shaking for another 8 hours at 35 ° C and 5 bar. The catalyst is filtered under a N2 atmosphere, the filtrate is concentrated to dryness under vacuum and the residue is dried under vacuum at 40 ° C.

Yield: 273 mg (92% of theory)

Mass Spectrum: m / e 371 (M + H)

In addition, compounds of the general formula 1 with Z = O, R = NO2 and NH2 and R2 = aryl, aralkyl, heteroaryl, heteroaralkyl and the allylaminocarbonyl-2-methyl-prop-1-yl group can also be synthesized according to the process synthesis of scheme 2:

Scheme 2

<img file="ES2215768T3_D0004.tif" />

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N- (pyridin-4-yl) - [1- (4-aminobenzyl) indol-3-yl] glyoxylic acid amide

1^to stage

N- (pyridin-4-yl) - (indol-3-yl) glyoxylic acid amide

To a solution of 9 ml of oxalyl chloride in 100 ml of anhydrous ether is added dropwise at 0 ° C, a solution of 10 g (85.3 mmol) of indole in 100 ml of ether. The mixture is kept for 3 hours under reflux. Then it is added to

-5 ° C, dropwise, a suspension of 12 g (127.9 mmol) of 4-amino-pyridine in 500 ml of tetrahydrofuran, the reaction mixture is heated with stirring for 3 hours at reflux temperature and let it sit overnight at room temperature. It was filtered, the precipitate was treated with water and the dried compound was purified through a column of silica gel (silica gel 60, Firm Merck AG, Darmstadt) using the eluent methylene chloride / ethanol (10: 1, v / v).

Yield: 9.8 g (43.3% of theory)

Mass Spectrum: m / e 266 (M + H)

2nd stage

N- (Pyridin-4-yl) - [1- (4-nitrobenzyl) -indol-3-yl] glyoxylic acid amide (D-68836)

The N- (pyridin-4-yl) -indol-3-yl glyoxylic acid amide, obtained according to the 1st step (scheme 2), is reacted with 4-nitrobenzyl chloride according to the "benzylation prescription" (page 5 ) and the obtained N- (pyridin-4-yl) - [1- (4-nitrobenzyl) -indol-3-yl] glyoxylic acid amide compound is isolated.

Yield: 64% of theoretical

Mass Spectrum: m / e 401 (M + H)

3rd stage

N- (pyridin-4-yl) - [1- (4-aminobenzyl) indol-3-yl] glyoxylic acid amide (D-68838)

The N- (pyridin-4-yl) - [1- (4-nitrobenzyl) -indol-3-yl] glyoxylic acid amide, obtained according to stage 2 (scheme 2), is catalytically hydrogenated according to the "hydrogenation prescription" (page 7) and the obtained N- (pyridin-4-yl) - [1- (4-aminobenzyl) indol-3-yl] glyoxylic acid amide compound is isolated.

Yield: 94% of theoretical

Mass Spectrum: m / e 371 (M + H)

General prescription for preparing the compounds of general formula 1 according to scheme 2

1st stage

To a solution, prepared under a nitrogen atmosphere, of a simple amount from molar to in excess of 60% of oxalyl chloride in an aprotic or apolar solvent, such as, for example, in diethyl ether, methyl-tert-butyl ether, tetrahydrofuran, dioxane or also dichloromethane, at a temperature between -5 ° C and + 5 ° C the indole derivative dissolved in a solvent is added dropwise, for example as indicated above for oxalyl chloride, which may be unsubstituted or substituted at C-2 or on the phenyl ring. The reaction solution is then heated for 1 to 5 hours at a temperature between 10 ° C and 120 ° C, preferably between 20 ° C and 80 ° C, especially between 30 ° C and 60 ° C, and then the solvent. The remaining residue of the (indole-3-yl) glyoxylic acid chloride is dissolved or suspended in an aprotic solvent such as, for example, tetrahydrofuran, dioxane, diethyl ether or toluene, or else in a bipolar aprotic solvent such as, for example, dimethylformamide, dimethylacetamide or dimethylsulfoxide, is cooled to a temperature between -10 ° C and + 10 ° C, preferably at -5 ° C to 8 ° C, and in the presence of an acid scavenger it is mixed with a solution of the primary or secondary amine in a diluent. As diluents, the solvents used for the dissolution of "indolyl-3-glyoxylic acid chloride" are considered. The acid scavengers used are triethylamine, pyridine, dimethylaminopyridine, basic ion exchangers, sodium carbonate, potassium carbonate, powdered potassium hydroxide, as well as excess primary or secondary amine used to stop the reaction. The reaction occurs at a temperature of 0 ° C to 120 ° C, preferably 2080 ° C, especially between 40 ° C and 60 ° C. After a reaction time of 1-4 hours and standing for 24 hours at room temperature, it is filtered, the precipitate is digested with water, filtered with suction and dried under vacuum. The desired compound is purified by recrystallization from an organic solvent or by column chromatography on silica gel or aluminum oxide. The eluent used is, for example, a mixture of dichloromethane and ethanol (10: 1, vol / vol).

ES 2 215 768 T3

2nd stage

The "indol-3-yl-glyoxylic acid amide", obtained according to the previous prescription of the 1st step, is dissolved in a protic, dipolar aprotic or apolar organic solvent, for example in isopropanol, tetrahydrofuran, dimethylsulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dioxane, toluene or methylene chloride, and is added dropwise to a suspension of a molar base or used in excess prepared in a three-neck flask under an atmosphere of N2 such as, for example, sodium hydride, powdered potassium hydroxide, potassium tert-butylate, dimethylaminopyridine or sodium amide, in a suitable solvent. The desired alkyl, aralkyl or heteroaralkyl halide is then added, undiluted or in a diluent, which was also used, for example, to dissolve the "indol3-yl-glyoxylic acid amide", optionally with the addition of a catalyst, for example copper, and it is allowed to react for some time, for example 30 minutes up to 12 hours, keeping the temperature within a range between 0 ° C and 120 ° C, preferably between 30 ° C and 80 ° C, especially between 50 ° C and 70 ° C.

Once the reaction has finished, the reaction mixture is introduced into water, the solution is extracted, for example, with diethyl ether, dichloromethane, chloroform, methyl-tert-butyl ether, tetrahydrofuran or n-butanol and the organic phase obtained in each case is dried over anhydrous sodium sulfate. The organic phase is concentrated in vacuo, the remaining residue is crystallized by mixing in a mortar or the oily residue is purified by distillation, or by column or flash chromatography on silica gel or aluminum oxide. The eluent used is, for example, a mixture of methylene chloride and diethyl ether in the ratio 8: 2 (vol / vol), or a mixture of methylene chloride and ethanol in the ratio 9: 1 (v / v).

3rd stage

The N-nitrobenzyl substituted “indoleglyoxylic acid amide”, obtained according to the above prescription (2nd step), is dissolved in a protic solvent such as, for example, methanol, ethanol, propanol or butanol, or in an apolar solvent, for example tetrahydrofuran, dioxane or glycol dimethyl ether, or in a bipolar aprotic solvent such as, for example, dimethylsulfoxide, dimethylformamide, dimethylacetamide or N-methylpyrrolidone, and the solution is mixed under nitrogen atmosphere and stirring with a hydrogenating catalyst such as, for example, Raney nickel, palladium / carbon or platinum. Hydrogen is introduced into the suspension under moderate shaking with a gas pressure of 1-15 bar, preferably 2-10 bar, especially at 4-6 bar, and the temperature is increased to approximately 20 ° -80 ° C, preferably 30 ° -60 ° C, especially at 45 ° -55 ° C. Eventually, after about 1 hour, a quantity of catalyst is added again and the hydrogenation continues. After a reaction period of 4-6 hours, the hydrogenation was complete. The catalyst is filtered under a nitrogen atmosphere, the solvent is concentrated to dryness and the residue from colorless to yellowish is dried under vacuum at 40 ° C.

According to this general prescription for steps 1-3, on which synthesis scheme 2 is based, compounds D-68836 and D-68838 were synthesized, which were also represented already according to the synthesis process of reaction scheme 1.

In a tubulin polymerization test the activity of the present compounds could be demonstrated. In particular, D-68838 was shown to inhibit tubulin polymerization and thus exert a destabilizing effect on microtubules or mitotic spindles.