A process for the eco-friendly preparation of 3, 5-dibromo-4-hydroxybenzonitrile

摘要

A highly pure 3,5-dibromo-4-hydroxybenzonitrile (bromoxynil) has been prepared in high yield from 4-hydroxybenzonitrile using eco-friendly brominating reagent comprising of 2:1 mole ratio of bromide to bromate salts in aqueous acidic medium without any catalyst under ambient conditions with no work up procedure. The product 3,5-dibromo-4-hydroxybenzonitrile was obtained in 91-99% yield with melting point 189-191°C and more than 99% purity by gas chromatographic analysis without any purification.