H. Akimoto, A. Kawai, H. Nomura
1985
Citations
0
Influential Citations
14
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
The carcinogenic γ-carbolines 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (2) were synthesized efficiently by the following procedures. The key method involved the acid-catalyzed cyclization of 2-acetamido-3-(2-indolyl)alkanoic acids to 1,2-dihydro-γ-carbolines. This was followed by dehydrogenation to the γ-carbolinecarboxylates and conversion of the ester group to the carboxyl and finally to the amino one by Curtius rearrangement. Alternative methods involved the thermolysis of 4-(1-benzotriazolyl)-3,6-dimethyl-2-pyridinamine to synthesize 1 and the condensation of 3-acetylindole-2- acetonitrile with ammonia to synthesize 2. The structures of γ-carbolines 1 and 2 were unambiguously established by comparing samples of each synthesized by the two different routes. A selective and one-step synthesis of ethyl 2-acetamido-3-(2-indolyl)alkanoates was newly exploited starting from diethyl acetamidomalonate and quaternary ammonium salts of 2-[1-(dimethylamino)alkyl...