Preparation of organic peroxides

A process for preparing an organic peroxidic composition, consisting essentially of a compound having the general formula ##STR6## wherein R.sub.1 and R.sub.4 each are selected from the group consisting of hydrogen and a lower alkyl group, R.sub.2 and R.sub.3 may be the same or different and each is selected from the group consisting of branched alkyl group having from 1 to 12 carbon atoms, an unbranched alkyl group having from 1 to 12 carbon atoms, a branched alkyl group having from 1 to 12 carbon atoms substituted with a group selected from the group consisting of hydroxy, lower alkoxy, lower alkoxycarbonyl, halogen and phenyl, an unbranched alkyl group having from 1 to 12 carbon atoms substituted with a group selected from the group consisting of hydroxy, lower alkoxy, lower alkoxycarbonyl, halogen and phenyl;

• phenyl, phenyl substituted with a group selected from the group consisting of lower alkoxy and halogen, and wherein R.sub.1 together with R.sub.2, R.sub.3 together with R.sub.4 form a branched or unbranched alkylene group having a total 12 carbon atoms and 5 or 6 carbon atoms in the nucleus, and wherein R.sub.1 together with R.sub.4 form a lower alkylene group, comprising
• reacting carbonyl compounds having the formulae ##STR7## wherein the symbols R.sub.1, R.sub.2, R.sub.3 and R.sub.4 have the meanings as defined, with hydrogen peroxide
• in an organic solvent, which forms an azeotrope with water and wherein both the starting carbonyl compound and the peroxidic composition formed are substantially soluble, said solvent being other than the starting carbonyl compound,
• in the presence of an acid catalyst selected from the group consisting of mineral acids, strong organic acids, and strong acid ion exchangers, in an amount of 0.2-200 mg equivalent per mole of said carbonyl compounds,
• at a temperature of 10.degree.-50.degree. C.
• while simultaneously removing water by distillation under reduced pressure.