Light coloured alpha-sulpho-fatty acid alkyl ester salt prodn. - by sulphonating ester with sulphur tri:oxide gas using cyclic nitrogen base as antioxidant

摘要

Prodn. of lightly-coloured alpha-sulpho-fatty acid alkyl ester salts (I) comprises sulphonating fatty acid alkyl esters (II) with SO3 gas and working up the prod.. Sulphonation is carried out in the presence of 0.05-0.2 mol-% w.r.t. (II), of cyclic N mole base(s), (III), i.e. pyridine (IIIA), pyrazine, picoline, pyrazidine, pyrimidine, piperidine, pipecoline, piperidone, pyrrole, pyrrolidine, pyrrolidone, pyrroline, pyrazole, pyrazoline and pyrazolone and their mono- and dicarboxyic acids and 1-4 C alkyl esters. Pref. (III) is used in an amt. of 0.1-0.15 mole-% w.r.t. (II) and pref. is (IIIA) or pyridinecarboxylic acid. (II) is a 12-18C fatty acid methyl ester. ADVANTAGE - (III) acts as antioxidant, inhibiting the formation of coloured oxo cpds..