Synthesis of some pyrazino, pyrimido and mercaptopyrimido annelated carbazoles using 2-hydroxymethylene-1- oxo-1,2,3,4- tetrahydrocarbazoles

Abstract

Treatment of 1-oxo-2-hydroxymethylene-1,2,3,4- tetrahydrocarbazole 1 with hydrazine hydrate, hydroxylamine hydrochloride, urea and thiourea in the presence of gl. acetic acid afforded the novel carbazole derivatives namely 4,5-dihydro-2H-pyrazino [3,4-a] carbazoles 2, 2-cyano-1- hydroxycarbazoles 3, 2,4-dihydroxy-1,4,5,6- tetrahydropyrimido[4,5-a]carbazoles 4 and 4-hydroxy-2-mercapto-1,4,5,6- tetrahydropyrimido- [4,5-a]carbazoles 5 respectively.