Process for the preparation of anhydrous n-(3-chloro-2-hydroxypropyl)

Abstract

The preparation of anhydrous, pure, crystalline N-(3-chloro-2-hydroxypropyl) trialkylammonium salts is disclosed by a process entailing reaction of epichlorohydrin with a trimethylammonium salt in an organic solvent which is a solvent for the two reactants and a non-solvent for the reaction product. A fine crystalline, chemically pure, anhydrous N-(3-chloro-2-hydroxypropyl) trimethylamine hydrochloride is produced by a process that does not entail an aqueous medium or the use of gaseous trimethylamine. The process comprises reacting trimethylammonium chloride with epichlorohydrin in an organic solvent which is a solvent for either of the two reactants and a non-solvent for the reaction product. Though a number of organic solvents may be used, it was found that chloroform was particularly suited. The reaction proceeds readily at temperatures within the range of 0.degree. to 50.degree. C. and results, depending on the reaction conditions, in 80% to 97% yields of pure N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride with respect to the trimethylamine hydrochloride. The trimethylamine hydrochloride is the preferred starting material, however, the process may be applied to other trialkylamine hydrochlorides such as those containing alkyl groups with 2 to 12 carbon atoms, or those containing different alkyl groups. Furthermore, the process may also be applied to other trialkylammonium salts, such as other halides, nitrates, sulfates and perchlorates.