Pressure-catalytic hydrogenation of Organic Compounds by Molybdenum Sulfide Catalyst. XIII

Abstract

The reaction of preparing dodecanthiol by catalytic hydrogenation (reductive thiolation reaction) of dodecanoic acid with sulfur, in cyclohexane under pressure has been investigated by using MoS3 catalyst.The reaction was proceeded above 200°c and gave dodecanthiol as the main product with a small amount of di-dodecyl disulfide as a by-product. It was advantageous to heat at about 250°c for this reaction and the amount of sulfur had great effect on the velocity of reaction. In case of 3.0 molar ratio of surfur with the reaction time of 240 min at 250°c, 90% yield of the thiol was obtained. It, was indicated from the result of similar reaction on dodecanoic anhydride and hydrogenation of thiododecanoic acid that the reducive thiolation reaction of dodecanoic acid consisted of the formation of thionic acid from reaction of H2S with dodecanoic acid and its rapid cleavage into the thiol.