Preparation of New Nitrogen-Bridged Heterocycles. 45. Smooth Hydrolysis of 6-Membered Heterocyclic 2-Imines with Partial Aromaticity

Abstract

The treatment of 2H-pyrano[2, 3-b]indolizin-2-imines and 2H-thiino[3, 2-a]indolizin-2-imines with acetic acid at reflux temperature smoothy afforded the corresponding 2H-pyrano[2, 3-b]indolizin-2-one and 2H-thiino[3, 2a]indolizin-2-one derivatives in moderate to good yields. An X-ray analysis of a 2H-thiino[3, 2-a]indolizin-2-one derivative was also performed.