A direct conversion of 5,6,7,8-tetrahydro-2H-1-benzo-pyran-2,5-diones into substituted 1-amino-5,6,7,8-tetra-hydroquinoline-2,5-diones

摘要

A highly selective transformation of 5,6,7,8-tetrahydro-2H-1-benzo-pyran-2,5-diones (1a-c) with hydrazides, arylhydrazines and heterocylic hydrazines as nitrogen-containing nucleophiles (2) into the corresponding 1-amino-5,6,7,8-tetrahydroquinoline-2,5-diones (5-17) was investigated. The reaction was carried out in the mixture of ethanol, water and triethylamine, and the corresponding quinoline-2,5-diones were obtained in 52-89% yields. The compounds (3) and (4) were proposed to be intermediates in this transformation.