PROCEDURE TO PREPARE N,N-DIMETHYLAMINOETHANOL 2-CHLOR-4-DIMETHYL-AMIDOSULFONYL-FENOXYACETATE HYDROCHLORIDE

摘要

The invention relates to a process for preparing 2-chloro-4-dimethyl-amido-sulphonyl-N,N-dimethyl amino ethanol phenoxy acetate hydrochloride, consisting of the ester interchange of the 2-chloro-4-dimethyl-amido-sulphonyl-phenoxy acetate ester with N,N-dimethyl-amino-ethanol for 4 hours, at 100 degree C in the presence of sodium N,N-dimethyl-amino-ethoxide as a catalyst, the resulting oily ester being further separated from the reaction medium, extracted and anhydrated with benzene at a temperature of up to 10 degree C, the anhydrous benzene solution being cold treated with hydrogen chloride, and the final product being purified by crystalline transformation from a mixture comprising ethanol and dimethyl formamide.