Prepn. of succinyl-choline-halide(s) - by reacting succinic acid di:alkyl ester with excess di:methyl-amino ethanol using alkali-alcoholate or -amide as catalyst, and reacting prod. with methyl halide

The prepn. of succinylcholine halide derivs. of formula (I) comprises (a) reacting a succinic acid dialkyl ester of formula (II) with excess dimethylamino methanol, in the presence of alkali-alcoholates or -amides as the catalyst and continuously distilling off the alcohol produced in the reaction; (b) recovering the excess dimethylamino ethanol, inactivating the catalyst and filtering it off; and (c) reacting the succinic acid bis-(2-dimethylaminoethyl ester) of formula (III) formed with a methyl halide to give (I). In formulae, X is Cl, Br or I; and R1 is 1-4C alkyl. USE/ADVANTAGE - (I) can be used as a muscle relaxant. (I) is obtd. in high yields and purity (unlike in previous processes). The dimethylaminoethanol acts simultaneously as reactant and solvent and the excess has no negative effect on the reaction.