CA1149385A

4-substituted imidazo [1,2-a] quinoxalines, and intermediates, and process for preparing the same

Abstract

ABSTRACT/ABRIDGEMENT Novel 4-substituted imidazo[1,2-.alpha.]quinoxalineshaving the general formula ,wherein X is -R1 or -NHR2 , wherein (1) R1 is bonded to a ring carbon by a carbon-to-carbon linkage and is an aliphatic, cycloaliphatic, substitutedphenyl, fused bicyclic aryl; or monocyclic aryl-substitutedaliphatic; and (2) R2 is a radical bonded to a nitrogen by a carbonto nitrogen linkage; said radical being selected from the groupconsisting of aliphatic, cycloaliphatic, phenyl, substitutedphenyl, fused bicyclic aryl or a monocyclic aryl-substitutedaliphatic group;and pharmaceutically acceptable salts thereof are disclosed whichhave several uses such as immunosuppressants, antifungal agentsand/or as anti-inflamatory agents. As disclosed are certain1-(2-acylaminophenyl)imidazoles useful in the preparation ofsaid 4-substituted imidazo [1,2-.alpha.]quinoxalines and the methodof preparing the 4-substituted imidazo[1,2-.alpha.]quinoxalines fromsaid 1-(2-acylaminophenyl)imidazoles by use of a cyclizing agent,e.g. phosphorous oxychloride.

Term

Term ended

Expired 5 July 2000, 26.2 years ago.

  1. Priority
  2. Filed
  3. Granted
  4. Expired
  5. Today

36 claims: 1 independent, 35 dependent

  1. 1
    The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:1. A process for preparing a 4-substituted imidazo [1,2-a]quinoxaline of the formula: in which -X is -R1 or -NHR2 wherein: (1) R1 is bonded to a ring carbon through a carbon-tocarbon linkage and is an aliphatic, cycloaliphatic, substituted phenyl, fused bicyclic aryl or monocyclic aryl substituted aliphatic group;and (2) R2 is a radical bonded to the nitrogen by a carbon to nitrogen linkage and selected from the group consisting of aliphatic, cycloaliphatic, phenyl, substituted phenyl, and fused bicyclic aryl, which process comprises reacting a 1-(2-acylaminophenyl)imidazole of the formula: - 55 in which X is as defined above, with cyclizing quantities of a cyclizing agent.
  2. 2
    The process according to claim 1 wherein said cyclizing agent is polyphosphoric acid or phosphorous oxychloride.
  3. 6
    The process according to claim 1, 2 or 3 wherein the reaction is carried out in the presence of an excess of pyridine.
  4. 22
    A 4-substituted imidazo[1,2-a]quinoxaline of the formula:or a pharmaceutically acceptable salt thereof wherein: (1) X is -R1 or NHR2;(2) R1 is bonded to a ring carbon through a carbonto-carbon linkage and is an aliphatic, cycloaliphatic, substituted phenyl, fused bicyclic aryl;or a monocyclic aryl substituted aliphatic group;and (3) R2 is a radical bonded to the nitrogen by a carbon to nitrogen linkage and selected from the group consisting of aliphatic, cycloaliphatic, phenyl, substituted phenyl, and fused bicyclic aryl, whenever prepared by the process of claim 3 or by an obvious chemical equivalent thereof. - 58