Process for the preparation of sodium methallyl sulfonate

摘要

Reaction of methallyl chloride (MAC) containing isocrotyl chloride (ICC) with aqueous sodium sulfite solution in an emulsion at 30 DEG -80 DEG C. and pH 7-11, maintained constant during the reaction by metered addition of sodium hydroxide solution is done in a two-step process, in the first step of which a mixture enriched in ICC and depleted in MAC from a preceding reaction batch and/or the second reaction step as excess organic residual phase, is reacted with an excess of concentrated sulfite solution until the MAC has been practically completely consumed; and, in the second step of which the reaction solution remaining after separating the unreacted ICC by distillation is reacted with a technical MAC/ICC mixture containing an excess of MAC until sulfite has been practically completely consumed. Thereafter, the excess organic residual phase is recycled to the first step after distillative separation. The MAC is preferably added in 10-40% excess in the second step.