2,3,7-Trimethyl-5- and 2,3,7-trimethyl-6-aminoindoles in the synthesis of pyrroloquinolines

Article abstract of DOI:10.1007/BF02290945

The possible utilization of 2,3,7-trimethyl-5- and 2,3,7-trimethyl-6-aminoindoles for different approaches to the synthesis of pyrroloquinolines was investigated. It was established that enamines, obtained from 2,3,7-trimethyl-6-aminoindole, undergo ready cyclization to substituted pyrrolo[3,2-g]quinolines, which is a convenient preparative method for their synthesis. It was shown that the peri-effect of the methyl group prevails over the ortho-effect of the methyl substituent at the position 7 with the ring binding of the pyridine nucleus to the benzene ring in the process of the cyclization of the corresponding 5-enaminoindoles. 1998 Plenum Publishing Corporation.