METHOD OF SYNTHESIS OF 5,7-DIBROMO-8-HYDROXYQUINOLINE Russian patent published in 1997 - IPC

FIELD: chemical technology, organic chemistry. SUBSTANCE: product: 5,7-dibromo-8-hydroxyquinoline that is synthesized by interaction of 8-hydroxyquinoline with bromine excess in chloroform medium at mass ratio of chloroform to 8-hydroxyquinoline = (15-30):1. Bromine is taken at amount not exceeding 1.1-fold stoichiometry value. After termination of reaction of 8-hydroxyquinoline interaction bromine excess is bound by addition of 8-hydroxyquinoline at stoichiometric amount to bromine excess in reaction mass followed by exposition of the latter. Isolation of 5,7-dibromo-8-hydroxyquinoline is carried out by precipitate filtration. Mother liquor is recovered to cycle, precipitate is treated with water at 90-100 C, an aqueous solution is cooled and the end product is isolated from an aqueous solution. EFFECT: increased purity of the end product, decreased reagents consumption. 5 cl