Opt. substd. benzyl alcohol and benzaldehyde prepn. - by reacting benzoic acid with ethyl or isobutyl chloroformate to give benzoyl-ethyl-carbonate, then catalytic hydrogenation and opt. oxidn.

摘要

Prodn. of aromatic alcohols and aldehydes comprises (a) reaction of benzoic acid or its derivs. with isobutyl or ethyl-chloroformate, in the presence of an anhydrous base and an ahydrous, inert solvent, at 5-10 degrees C and atmospheric pressure, to obtain the corresp. mixed anhydride (b) catalytic hydrogenation of the mixed anhydride from (a) at 55-65 degrees C and 10.5-17.5kg/cm2 for 8-12 hrs. to give the corresp. benzyl alcohol (c) oxidation of the benzyl alcohol from stage (b) to give the corresp. aldehyde. Prods. have numerous uses e.g. benzaldehyde is used in the mfr. of dyes, flavours, etc., is an intermediate for mandelic and cinnamic acid prodn. and a solvent; benzyl alcohol is used as a bacteriostat and as a solvent for gelatine, casein and cellulose acetate; 3,4,5-trimethoxybenzaldehyde is an intermediate for trimethoprim. and other pharmaceuticals.