METHOD FOR PREPARING 4,4'-DICHLORO-ORTHO-HYDROXY- DIPHENYL ESTER Russian patent published in 2004 - IPC

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to method for preparing 4,4'-dichloro-ortho-hydroxydiphenyl ester of the formula (1) that is used for protection of organic substances and objects from microorganisms. Method involves chlorination of diphenyl ester of the formula (5) (stage 1a) or interaction of para-chlorophenol of the formula (4a) and para- dichlorobenzene of the formula (4b) in stoichiometric ratios in the presence of copper and/or copper salts as catalyst and alkaline metal hydroxide (stage 1b); acylation of dichlorosubstituted compound of the formula (6) prepared at stage (1a) or (1b) under condition of Friedel-Crafts reaction (2-d stage); oxidation of prepared dichloroacyl compound of the formula (7) wherein R represents C₁-C₈-alkyl that is unsubstituted or substituted with 1-3 halogen atoms or hydroxy-group; unsubstituted C₆-C₁₂-aryl or C₆-C₁₂-aryl that is substituted with 1-3 halogen atoms, C₁-C₅-alkyl or C₁-C₈-alkoxy-group, or their combinations (3-d stage) and the following hydrolysis of prepared compound of the formula (8) wherein R means above indicated values (4-th stage). Method provides suppression of undesirable accompanying reactions. EFFECT: improved preparing method, enhanced economy. 11 cl, 3 ex