CARBAZOLE DERIVATIVE

PURPOSE:To obtain the new subject derivative useful as a therapeutic agent for cerebral apoplexy, cerebral hemorrhage, cerebral infarct, etc., protecting brain cells during ischemia in the brain, suppressing ischemic encephalopathy by reacting a carbazole with triphosgene and treating the reaction product with an amine. CONSTITUTION:Pyridine is added to a methylene chloride suspension of a carbazole of formula I [R1 to R8 are H, lower alkyl, (substituted) lower alkoxy, OH, acetoxyl, nitro, amino, halogen, etc.] (e.g. carbazole), the carbazole is reacted with triphosgene for 4 hours to give 9-chlorocarbonylcarbazole. The reaction mixture is reacted without isolation with ammonia or an amine of the formula R9H [R9 is group of formula II (R10 is H or lower alkyl; R11 is lower alkylamino, piperidino, etc.; n is 2-4) or formula III (R12 is H or lower alkyl; m is 2 or 3) or NH2] in the presence of a base to give the objective carbazole derivative of formula IV suppressing ischemic encephalopathy.