On the synthesis and isolation of chlorocarbazoles obtained by chlorination of N-substituted carbazoles

Chloro derivatives of N-methylcarbazole (1), N-phenylcarbazole (2), N-acetylcarbazole (3), N-benzoylcarbazole (4) and 2-methoxy-N-methylcarbazole are synthesized. They are compounds 1a, 1b, 1c, 1d, 1e, 2a, 2b, 3a, 3b, 3c, 3d, 4a, 4b, 5a, 5b, 5c, 5d and 5e. Some of them are described for the first time. By using semiempirical PM3 method theoretical substituent effects on the chlorinating reaction are calculated. A chlorination mechanism of carbazoles and N-substituted carbazoles are compared.