GB942367A - Continuous production of carboxylic acids from olefines, carbon monoxide and water - Google Patents

Abstract

In a process for the continuous production of aliphatic and cycloaliphatic carboxylic acids by reaction of olefines, alcohols, alkyl halides or mercaptans with carbon monoxide in presence of an inorganic strongly acid catalyst under increased pressure and at -25 to +40 DEG C., the catalyst and starting material are trickled under carbon monoxide pressure through a packed tower and the reaction product is hydrolysed with ice or water. Preferably the starting material is introduced into the tower below the point of introduction of the catalyst. In examples, using sulphuric acid catalyst, cyclohexene is converted to cyclohexane- and 1-methylcyclopentanecarboxylic acids, tertiary butyl alcohol to trimethylacetic acid and 2-ethyhexanol to a methyl-a -ethylcaproic acid. Other suitable starting materials are propylene, butylene, isobutylene, pentenes, hexenes, nonenes, hexadecenes, cyclooctene, cyclododecene, isopropanol, methyl isobutyl carbinol, cyclohexanol, methylcyclohexanol, decahydronaphthol, octanol, sec. or tert. butylmercaptan, decyl and dodecyl mercaptans, tert-butyl and cyclohexyl chlorides and 2-ethylhexylbromide. Alternative catalysts are boron triflouride (or hydrates) and phosphoric acid. The starting materials may be dissolved in inert solvents (cyclohexane in examples) e.g. n-octane, or cyclo-pentane or -octane. The tower packing may be e.g. cylindrical, annular, conical or saddle-shaped; aluminium oxide strands and Raschig rings are used in examples, while active carbon and alloy steel are also suitable.