Diol prepn. by hydrogenating carboxylic acid(s) - with phosphoric acid or phosphate ester addn. to prevent deposit formation

摘要

H3PO4 or a phosphate ester is added to 6 C mono- and/or dicarboxylic acids, esp. the acid mixts. obtd. as by-prods. in cyclohexane oxidn. to cyclohexanone, before their hydrogenation to 6 C alpha, omega-diols. Phosphoric acid or phosphate quantity added may be 10-100 ppm. w.r.t. aq. solns. The phosphates may be derived from 1-20 C alcohols. The formation of residues, i.e. 'cork' formation, causing clogging of plant, is prevented.