Iso-butyryl fluoride prodn. by two=stage process - comprising reacting propylene@ with hydrogen fluoride in gas phase until before pt where oligomers form, then reacting with carbon mon:oxide in liq. hydrogen

摘要

Iso-butyryl fluoride prodn. from propylene in two stages comprises (1) reacting propylene with HF in the gaseous phase up to the point just before propylene oligomers are formed, this produces a gaseous mixt., mainly of isopropyl fluoride with a small amt. of unreacted propylene, and (2) reacting the gaseous mixt. from the first stage without sepn. and after compression with CO in liq. HF. USE/ADVANTAGE - Iso-butyryl fluoride is very active and easily hydrolysed to isobutyric acid, from which methacrylic acid and methyl methacrylate (precursor of polymethyl methacrylate plastics) can be obtd. The two-stage-two phase process gives better yields than methods using only carbonylation of propylene:carbonylation jointed, of isopropyl fluoride with residual propylene avoids the risk of heavy prod. formation (polymers) which would be difficult to separate off, on an industrial scale. The process can be carried out continuously or discontinuously, the reactor being of a tubular form contg. a catalyst, the attached diagram shows a continuous system for the process.