| 摘要 |
Mercaptans of high molecular weight are prepared by passing the vapour of saturated or unsaturated aliphatic or cycloaliphatic alcohols containing at least twelve carbon atoms together with hydrogen sulphide over dehydrating catalysts at elevated temperature, preferably 150--450 DEG C. Increased or reduced pressure may be employed and inert gases or vapours, e.g. nitrogen, carbon dioxide or steam, may be present. Catalysts mentioned are the oxides, phosphates, halides, sulphates and sulphides of beryllium, magnesium, calcium, strontium, barium, manganese, cadmium, zinc, copper, nickel, iron, titanium, zirconium, cerium, thorium, lead, phosphorus, vanadium, chromium, molybdenum, tungsten and uranium; surface-active catalysts are also suitable. The products are useful for the manufacture of textile assistants and dyestuffs. Examples describe the preparation of (1) octodecyl mercaptan from octodecyl alcohol using granular zirconium dioxide, or a mixture of zirconium dioxide and pumice meal, or active charcoal which may be activated with phosphoric acid; (2) octodecenyl mercaptan from octodecenyl alcohol using an aluminium oxide catalyst; (3) dodecyl mercaptan from dodecyl alcohol using titanium dioxide; (4) octodecenyl mercaptan from octodecenyl alcohol using the catalyst of (1); decahydro-a -naphthol is similarly converted into the mercaptan; (5) cetyl mercaptan from cetyl alcohol using zirconium oxide; (6) 1-mercapto-octodecylene from octodecane-1 : 12-diol using a bauxite catalyst. The treatment of alcohols obtained by oxidizing paraffin waxes or by hydrogenating the fatty acids of natural glycerides is referred to. Mixtures of the high-molecular alcohols with alcohols of low molecular weight may also be treated, in which case mixtures of mercaptans of high and low molecular weight are obtained. Octodecenyl alcohol is prepared by the partial hydrogenation of oleyl aldehyde. |
