Cyclohexanol from cyclohexene via cyclohexyl acetate: catalysis by ion-exchange resin and acid-treated clay

Abstract

Esterification of acetic acid with cyclohexene was carried out in the temperature range of 70-120°C with Amberlyst-15 (cation-exchange resin) and Filtrol-24 (acid-treated clay) as catalysts. The effect of the mole ratio of acetic acid to cyclohexene and the effect of the temperature on the selectivity of the ester (cyclohexyl acetate) were studied. The possibilities of using aqueous acetic acid to produce cyclohexyl acetate and cyclohexanol simultaneously were also explored. Transesterification of cyclohexyl acetate with n-butanol was studied in the temperature range 120-160°C with the above catalysts. The transesterification reaction was accompanied by a side reaction leading to the formation of butyl cyclohexyl ether which may well be of value to the perfume industry. Optimum conditions for selectively producing cyclohexanol were delineated. It was also possible to change the operating conditions to give up to 80% butyl cyclohexyl ether.