| abstract |
1350328 Alkanesulphonic acids and chlorides PENNWALT CORP 19 May 1972 [28 May 1971] 23732/72 Heading C2C A continuous method for the preparation of alkane sulphonic acids of the formula RSO 3 H, where R is C 1 -C 4 alkyl or substituted alkyl, comprises continuously feeding an alkyl mercaptan or dialkyl disulphide of the formula RSX, where X is H or an SR group, and at least the stoichiometric amount of chlorine to a reaction zone containing aqueous hydrochloric acid solution maintained at a temperature of from 85-115‹ C., said reactants being fed into the aqueous hydrochloric acid solution at a rate sufficient to achieve a vigorous evolution of hydrogen chloride gas with concomitant turbulence and intimate contact of the reactants in the reaction zone, continuously withdrawing from said reaction zone and passing to a product recovery zone a stream of hydrochloric acid solution containing product alkane sulphonic acid, withdrawing from said recovery zone a side stream containing product alkane sulphonic acid and recycling the rest of the alkane sulphonic acid-containing hydrochloric acid solution as a recycled stream from said recovery zone to said reaction zone. In a modification the temperature is above 65‹ C. but less than 85‹ C. and alkanesulphonic acid chloride is formed in addition to the acid. |