GB785607A - Manufacture of organic hydroperoxides - Google Patents

Abstract

The process of the parent Specification is modified in that the feed of diisopropylbenzenes which is oxidized to the dihydroperoxides, is substantially free from trimethylindane and o-diisopropylbenzene, and is produced by the alkylation of benzene or cumene, or by the disproportionation of o-diisopropylbenzene or poly-isopropylbenzenes, in the presence of aluminium chloride as catalyst, and under reaction conditions whereby substantially no trimethylindane or o-diisopropylbenzene is produced. The interrelated factors required to achieve, either by alkylation or disproportionation, a feed as defined above, are reaction temperature and amount and type of catalyst. The specified temperature range is about 40-115 DEG C., the reaction time and amount and type of catalyst being adjusted accordingly. The specified amount of catalyst is between 0.1 and 12 mols. per mol. of benzenoid material. The aluminium chloride catalyst may be activated by treatment with hydrogen chloride or isopropyl chloride. A liquid ternary complex alkylation catalyst, prepared for example by agitating a mixture of 1 mol. of mono- or poly-isopropylbenzene and 1 mol. of aluminium chloride while adding half a mol of isopropyl chloride, is preferred. The alkylation is carried out on benzene or cumene using as alkylating agent n- or iso-propanol, isopropyl chloride, or preferably propylene. In examples: (1) cumene was alkylated with propylene at 60 DEG C. using unactivated aluminium chloride as catalyst, to give a feed consisting of m- and p-diisopropylbenzenes and almost free of trimethylindane, and this feed was oxidized by the process of the parent Specification, the result being compared with that obtained with a feed containing 11 per cent of trimethylindane; (2) benzene was alkylated with propylene at 60 DEG C., using a catalyst prepared by passing hydrogen chloride through a mixture of aluminium chloride and cumene, and the product analysed; (3) benzene was alkylated with propylene at 80 DEG C. using unactivated aluminium chloride as catalyst and a mixture containing mono-, di- and poly-isopropylbenzenes was obtained, the di-isopropylbenzene fraction being free of the o-isomer and trimethylindane. A table is given showing the effect of various reaction temperatures on the composition of the alkylate, when using the procedure of (1).