Reactions of 4-arylmethylenepyrrolidine-2,3-diones. Synthesis of pyrrolo[3,4-b]-pyridines and -quinolines

Abstract

4-Arylmethylenepyrrolidine-2,3-diones (1) condense with ethyl β-aminocrotonoate or with 4-aminopent-3-en-2-one to give adducts which can be dehydrogenated to afford pyrrolo[3,4-b]pyridines. N-Phenacylpyridinium salts also react with the pyrrolidinediones (1), to form 2,4-diarylpyrrolo[3,4-b]pyridines. In addition, o-nitrobenzylidenepyrrolidine-2,3-diones undergo reductive cyclization to give pyrrolo[3,4-b]quinolines.