Heterocyclization of 2-nitrobenzoyl1,1,3,3-tetracyanopropenides by the action of hydrogen chloride in alcohol

Abstract

The interaction of 2-[3(4)-nitrobenzoyl]-1,1,3,3-tetracyanopropenides with hydrogen chloride in alcohols leads to the corresponding 4-amino-1-alkoxy-1-[3(4)-nitrophenyl]-3-oxo-6-chloro-2,3-dihydro-1 H -pyrrolo[3,4- c ]pyridine-7-carbonitrilam, through the formation of intermediate 2-{2-hydroxy-2-[3(4)-nitrophenyl]-4-cyano-5alkoxy-1,2-dihydro-3 H -pyrrole-3-ylidene}malononitriles, which can be isolated in low yield. Carrying out the reaction in an aqueous-alcoholic medium makes it possible to obtain 4-amino-1-hydroxy-1-[3(4)-nitrophenyl]3-oxo-6-chloro-2,3-dihydro-1 H -pyrrolo[3,4- c ]pyridine-7-carbonitriles.