The chemistry of carbazole. VI. On the formation of <i>N</i>‐ethylcarbazoles in the cadogan reaction

Abstract

Abstract Reaction of 2′,6‐dimethyl‐2‐nitrobiphenyl with triethyl phosphite gave 4,5‐dimethyl‐9‐ethylcarbazole besides 4,5‐dimethylcarbazole. In this reaction, 4,5‐dimethylcarbazole was ethylated by triethyl N ‐(2′,6‐dimethybiphenyl‐2‐yl)phosphorimidate and diethyl N ‐(2′,6‐dimethylbiphenyl‐2‐yl)phosphoramidate, which arose from a nitrene‐intermediate and triethyl phosphite. Analogous ethylations of carbazole with other phosphorimidate and phosphoramidates were investigated.