Recyclization of indolo[2,3-c]pyrylium salts by reaction with secondary amines
Abstract1-R-3-methylindolo[2,3-c]pyrylium salts react with cyclic secondary amines (morpholine, piperidine, and N-methylpiperazine) to give, depending on the structure of the alkyl substituent R, either 1- (when R=Me) or 3-aminocarbazoles (when R=i-Pr), or mixtures of both (when R=Et). The position of the amino-substituent in 1-morpholino-3,9-dimethylcarbazole has been established by x-ray diffraction examination.