Resolution of racemic albuterol via diastereomeric salts formation with di-p-toluoyl-D-tartaric acid.

Abstract

A convenient method is described for the resolution of racemic Albuterol by selective crystallization of its di-p-toluoyl-D-tartrate salt. The separation resulted in a 38% yield of the (R)-enantiomer. Racemization of the (S)-enantiomer occurs in diluted H2SO4 at 100 degrees C in 80% yield. This racemic mixture was recycled to the diastereomer salt, in order to improve the overall yield. The (R)-Albuterol tartrate salt was decomposed in a sulfuric acid solution, and the (R)-Albuterol was isolated as its sulfate salt with 67% overall yield with 99.5% optical purity.