Total Synthesis of Pyrrolnitrin. V. Synthesis of Pyrrolnitrin and Its Analogues. (1)

Abstract

The structure for pyrrolnitrin by chemical degradation was established. Pyrrolnitrin, 3-(2-nitro-3-chlorophenyl)-4-chloropyrrole (XIIIa), and several 3-aryl-4-chloropyrroles (XIII) were derived from ethyl 3-aryl-5-trichloromethyl-4-chloro-2-pyrrolecarboxylates (VII) via 3-aryl-4-chloro-2, 5-pyrroledicarboxylic acids (X). VII could be obtained by exhaustive chlorination of three kinds of starting materials, ethyl 3-aryl-5-methyl-2-pyrrolecarboxylates (I), 2-ethoxycarbonyl-3-aryl-5-methyl-4-pyrrolecarboxylic acids (III) and ethyl 3-(2-nitro-3-chlorophenyl)-4-chloro-5-methyl-2-pyrrolecarboxylate (IVa).