The Synthesis of Aminoalcohols from Epoxides and Ammonia

Abstract

In connection with another problem we had need for some simple aminoalcohols which were not commercially available. While textbooks make the reaction of ammonia and amines with epoxides appear inviting for the preparation of aminoalcohols, an examination of the literature yielded surprisingly few clearly written examples of the reactions of ammonia with epoxides and many of the good examples had undesirable features. For instance, one of the aminoalcohols desired was threo-3-amino-2-butanol. Lucas et al^2. reported an improved synthesis of this compound in 76% yield by reacting the meso-epoxide with an excess of concentrated aqueous ammonia. The drawbacks to their synthesis were the long recommended reaction time (10 days) and the large volume of water to be removed by distillation (about 2 liters per mole of product obtained). While the yield is reasonably good, all other examples of the reaction that we have found report lower yields (18–70%). Malinovski³ has reviewed the general reaction and treats the side reaction products obtained. Our procedure does not totally avoid side reactions, but the time involved and the good yields make this method more attractive than former procedures for the derivatives that we have prepared.