Ring transformation of chromone-3-carboxylic acid under nucleophilic conditions

Abstract

The effect of sodium hydroxide solution on chromone-3-carboxylic acid (1) afforded ù-formyl-2-hydroxyacetophenone (2) and 1-(3-chromonyl)-2-(2- hydroxybenzoyl)ethene (3). The reactivity of carboxylic acid 1 towards primary and secondary amines, hydrazines, cyanoacetohydrazide, cyanoacetamide and malononitrile in different media led to interestingly ring transformation via ã-pyrone and carboxylic group. Structures of the products have been established on the basis of elemental analysis and spectral data. © ARKAT USA, Inc.