Synthesis of d-2-amino-1-butanol

Abstract From the Canadian patent

d-2-Amino-1-butanol, for the synthesis of ethambutol hydrochloride, d,d'-2,2'-(ethylenediimino)di-1-butanol dihydrochloride, is produced in high purity and good yields by the reaction of butene-l, a nitrile, preferably an excess of acetonitrile, and chlorine to form N-l-(chloromethyl)propylacetimidoyl chloride which is hydrolyzed to d1-2-amino-1-butanol, which can be isolated as the hydrochloride or free, base, or a mixture resolved with L(+)-tartaric acid and the d-2-amino-1-butanol reacted with ethylene dichloride and then hydrochloric acid to form ethambutol hydrochloride. A minimum of by-products which are conveniently split out permits the economical synthesis of a pharmaceutical grade …