SYNTHESIS OF PYRIDOCARBAZOLES FOR ANTI-TUMOUR STUDIES

Cyclodehydration in orthophosphoric acid of the azomethines of 3-formyl-carbazoles and aminoacetals has yielded 5-methyl-(IId), 3,5,11-trimethyl-(11b), 3,5,9,11-tetramethyl-(IIc), and 5,7,10,11-tetramethyl-6H-pyrido[4,3-b]carbazoles (IIa). In the same way γ-carboline and 6,9-dimethyl-γ-carboline were obtained from the azomethines of 3-formyl- and 3-formyl-4,7-dimethyl-indole. A Doebner reaction with 3-amino-2-methylcarbazole, acetaldehyde, and pyruvic acid yielded 1-carboxy-3,5-dimethyl-7H-pyrido[2,3-c]carbazole (VIIIb) from which was derived the methyl ester (VIIIc) and 3,5-dimethyl-7H-pyrido [2,3-c]carbazole (VIIIa). © 1969, CSIRO. All rights reserved.