Percarboxylic acids prepn. from acid chlorides in soln. - using conc. hydrogen peroxide, opt. with pyridine

摘要

Prepn. of peroxycarboxylic acids is by reaction of conc. H2O2 on a carboxylic acid chloride in soln. in THF, diethyl ether or dioxan at -20 to +30 degrees C., opt. in the presence of pyridine. The H2O2 pref. has a concn. of =30 wt.%, esp. 85 wt.% and is usually used in excess, partic. in a molar ratio of approx. 2:1, based on wt. of acid chloride. The min. amt. of solvent required to dissolve the reactants is pref. used and pref. 0.5 mol. equiv. of pyridine are used when aliphatic acids are prod. and 0.125 mol. equiv. for other types. Prodn. of aliphatic, aromatic and substd. polycarboxylic acids is possible in high yields, e.g. 75-85%, without simultaneous prodn. of organic peroxides. Acidification of reaction mixt. is avoided thus allowing prepn. of percarboxylic acids with ester functions.