Tetrahedron

Double cyclisation of phenylglycine-o-carboxylic acids—I: New stable mesoionic oxazolones

E Tighineanu, F Chiraleu, D Råileanu

Index: Tighineanu, Elena; Chiraleu, Filip; Raileanu, Dan Tetrahedron, 1980 , vol. 36, p. 1385 - 1397

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Citation Number: 13

Abstract

Remarkably stable mesoionic oxazolones possessing an oxazolo [3, 2-a] quinolinium structure (5a–b), 8, 16, 17) were obtained by the double cyclisation of phenylglycine-o- carboxylic acids (3a–c) in refluxing acetic anhydride or in benzoic anhydride at 140°, The 0- Ac group was eliminated to give the corresponding lactones (6a–b) or replaced by O-Ts (7). IR stretching vibrations of the endo-carbonyl were in the range 1710–1768 cm− 1, while ...