Patent GB-427903-A (GB)
Title: Improvements in the manufacture and production of organic sulphur compounds
IPC: C07B45/06
Filed: 1933-11-25
Abstract: Organic sulphur compounds for use as intermediates in the preparation of dyestuffs, pharmaceutical products, assistants for the textile industry or vulcanization accelerators are produced by the action of acetylene in the gaseous or liquid phase, if desired under increased pressure on a mercaptan of the aliphatic, aromatic or heterocyclic series at a temperature between 50 and 300 DEG  C. in the presence of either a basic metal compound or of a zinc or cadmium salt of an organic acid.  Examples of mercaptans are methyl, ethyl, butyl, hexyl, dodecyl, octodecyl, and benzyl mercaptan, thiophenol, thiocresol, thionaphthol, and 2-mercaptobenzothiazole, also polyvalent mercaptans such as ethylene-di-mercaptan, and thioresorcinol.  Basic metal compounds suitable as catalysts are the oxides, hydroxides, sulphides, sulphides, acetates, phenolates, alcoholates, mercaptides and silicates of the alkali and alkaline earth metals, and as suitable salts of zinc or cadmium there may be used, the formates, acetates, stearates, benzoates and phthalates, or mixtures of these substances if desired with the addition of mercury compounds.  The catalysts may be employed as such in a solid or dissolved or suspended form preferably in organic media or on carrier substances such as active carbon, kieselguhr or pumice. The process may be continuous or discontinuous; when using the continuous process it is preferable to use a pressure tight pipe system.  Suitable liquids in which to suspend or dissolve the catalyst are di- or tri-ethylene glycol.  The course of the reaction is influenced by the catalyst, thus, when a basic metal compound is used, the acetylene most frequently enters the --SH group of the mercaptan forming the corresponding thiovinyl ether of the general formula R--S--CH : CH2. In the presence of zinc and cadmium compounds, the thiovinyl ether is also first formed, but in this case a further molecule of the original material adds on to yield an ether of ethane dithiole of the general formula R--S--CH2--CH2--S--R.  It is, however, possible when using basic catalysts to so adjust conditions that the ethane dithiol ether is formed.  The following examples are specified: (1) a mixture of nitrogen and acetylene is passed into a stirring autoclave containing thiophenol, butanol and caustic potash; the gas is passed for 12 hours at 160 DEG  C. and 15 atmospheres pressure; thiophenol vinyl ether (C6H5--S--CH : CH2) is produced; p-thiocresol may be substituted for thiophenol to yield para-thiocresol vinyl ether, beta-thionaphthol to yield beta-thionaphthol vinyl ether, and 2-mercaptobenzothiazole to yield 2-mercaptobenzothiazole vinyl ether. (2) If zinc acetate is substituted for caustic potash in example 1 thiophenol yields 25 per cent of thiophenol vinyl ether and 75 per cent of ethane-dithiol-diphenyl ether (C6H5--S--CH2m1 CH2--S--C6H5) and para-thiocresol yields a mixture of para-thiocresol vinyl ether and ethane - dithiol - di - para - tolyl - ether.  (3) A mixture of nitrogen and acetylene passed into ethyl mercaptan in which sodium is dissolved to yield a mixture of thiovinyl ethyl ether and ethane dithiol diethyl ether.  (4) Acetylene led into para-thiocresol containing zinc acetate yields para-thiocresol vinyl ether and ethane dithiol di-para-tolyl ether.  (5) Ethane mercaptan vapour and acetylene vapour are led under pressure into a solution of potassium sulphide in diethylene glycol and yield equal parts of thiovinyl ether and unchanged ethyl mercaptan.  (6) Nitrogen and acetylene is passed in a mixture of 1-mercapto-2-5-dimethyl-4-chlorobenzene, butanol, and caustic potash in a stirring autoclave under pressure at raised temperature to yield a thiovinyl ether of the formula <FORM:0427903/IV/1> (7) Nitrogen and acetylene is passed into a stirring autoclave containing benzyl mercaptan, butanol and caustic potash to yield thiovinyl benzyl ether of the formula C6H5.CH2.S. CH : CH2; if dodecyl mercaptan is substituted for benzyl mercaptan thiovinyl dodecyl ether is obtained.  (8) Nitrogen and acetylene is passed into a mixture of 8-chlorothionaphthol, butanol, and caustic potash to yield 8-chlorothionaphthol vinyl ether.ALSO:Accelerators for the vulcanization of rubber are produced by the action of acetylene in the gaseous or liquid phase, if desired under increased pressure on a mercaptan of the aliphatic, aromatic, or heterocyclic series, at a temperature between 50 and 200 DEG  C. in the presence of a basic metal compound or of a zinc or cadmium salt of an organic acid, to produce either the corresponding thiovinyl ether of the general formula R-S-CH : CH2 or the corresponding ethane dithiole of the general formula R-S-CH2.CH2-S-R.  Many examples are given.