Oxidation of sec alcohols with cobalt salts - selectively to ketones

摘要

Liquid phase oxidation of sec. aliphatic alcohols not contg. a tert. H atom on a C atom in the alpha-pos. with respect to the C atom. carrying the OH gp. with selective formation of ketones having the same no of C atoms these ketones being suitable as solvents, plasticisers aromatisation agents, etc. is effected by contacting the alcohols, e.g. a mixture of sec. heptanols, with a Co salt in which the ratio of trivalent Co to total Co is 0.5-1 at 20-120 degrees C pref. 30-100 degrees C, esp. 50-70 degrees C suitably cobalt acetate, the conc of the Co salt being at least 0.05 pref. at least 0.1 mol/l reaction mixture. The Co salt acts as oxidant and the presence of O2 is not required the reaction proceeding in a comparable manner both in the presence of O2 or an inert atmos. e.g. N2. A solvent may be used e.g. acetic acid, thus a mixture of sec. heptanols yields 2-heptanone preferentially.