Unexpected Behavior of Enaminones: Interesting New Routes to 16-Naphthyridines 2-Oxopyrrolidines and Pyrano432-de16naphthyridines

摘要

Reaction of enaminones >1a–>d with 2-aminoprop-1-ene-1,1,3-tricarbonitrile (>2) in the presence of AcOH/NH4OAc afforded 7-amino-5-oxo-5,6-dihydro-1,6-naphthyridine-8-carbonitrile derivatives >9a–>d. On the other hand, 2-aminopyrano[4,3,2-de][1,6]naphthyridine-3-carbonitriles >20a–>c,>e were the only obtained products from the reactions of >1a–>d with >2 in the presence of AcOH/NaOAc, while >1d afforded [3,5-bis-(4-chloro-benzoyl)-phenyl]-(4-chloro-phenyl)-methanone >21 under the same condition. The reaction of >2 with diethyl acetylenedicarboxylate in the presence of AcOH/NH4OAc afforded (4-cyano-5-dicyanomethylene-2-oxo-2,5-dihydro-1H-pyrrol-3-yl)-acetic acid ethyl ester >15B.