Syntheses of 3-Bromochromones

Chemical Laboratory, Bhagalpur University, Bhagalpur-812 007

Fifteen 3-bromochromones have been prepared by brominatlng the corresponding hydroxyaroyl aroyl/heteroyl methanes and cyclization. Direct bromination of chromones to yield 3-bromocbromones has been studied by three different reagents, (i) bromine, (ii) N-bromosuccinimide and (iii) cupric bromide. Cupric bromide gives the best result. The chromone structures have been established by analysis, spectral data and their conversion to the corresponding coumaran-3-ones.