Process for the preparation of phenylpropanones

A process for the preparation of a phenyl-propanone having formula (I):

• ##STR7## wherein R and R.sub.1, which may be equal or different, are C.sub.1 -C.sub.4 alkyl groups or are attached to the CH.sub.2 group of a heterocyclic ring, characterized in that:
• (a) the corresponding allylbenzene having formula (II):
• ##STR8## is epoxidized with H.sub.2 O.sub.2 under stirring, at 40.degree.-90.degree. C., in a bisphasic system consisting of an aqueous phase containing H.sub.2 O.sub.2, and an organic phase consisting of at least one solvent immiscible in the aqueous phase selected from aromatic and chlorinated hydrocarbons, of said allylbenzene, and of a catalyst having the formula Q.sub.3 XW.sub.4 O.sub.24+, wherein Q is a quaternary cation (R.sub.2 R.sub.3 R.sub.4 R.sub.5 M), M being selected from the group consisting of N and P, and R.sub.2, R.sub.3, R.sub.4 and R.sub.5, which may be equal or different, are so selected from hydrogen and alkyl groups as to have from 1 to 4 alkyl groups containing, on the whole, from 20 to 70 C atoms, wherein X is P or As, and wherein the H.sub.2 O.sub.2 :
• allylbenzene molar ratio is from 1:1 to 1:2;
• (b) said solvent and catalyst are removed from the organic phase and, optionally, the pure epoxide, having formula (III):
• ##STR9## is isolated from the same organic phase;
• and (c) said epoxide or said organic phase, after said removal of (b), are isomerized by heating, under stirring, in the presence of catalytic amounts of LiI, at 90.degree.-150.degree. C.