METHOD OF SYNTHESIS OF 2,2-BIS-(3',5'-DIBROMO-4'-HYDROXYPHENYL)-PROPANE Russian patent published in 1995 - IPC

FIELD: chemical technology. SUBSTANCE: synthesis of 2,2-bis-(3',5'-dibromo-4'-hydroxyphenyl)-propane is carried out by bromination of diphenylolpropane with liquid bromine in solution of lower aliphatic alcohol at the molar ratio of diphenylolpropane:bromine = 1:(4-4.02) following by treatment of unreacted bromine with reducing agent and crystallization of the end product from alcohol. Bromine and solution of diphenylolpropane in 50-60% aqueous alcohol were fed to the reaction zone. Prepared precipitate is filtered off, dissolved in concentrated or water-diluted alcohol at concentration 50-100 wt.-%, and reducing agent (hydrazine hydrate) is added. Mixture is heated and kept for 0.5 h at temperature by 10-20 C below that of boiling point of alcohol used. Then product is precipitated from diluted alcohol at 15-20 C and filtered off. EFFECT: improved method of synthesis. 2 cl, 1 tbl