Design of an Integrated Process of Chromatography, Crystallization and Racemization for the Resolution of 2′,6′-Pipecoloxylidide (PPX)

An integrated process for the chiral separation of the industrially relevant substance 2′,6′-pipecoloxylidide (PPX), an intermediate in the manufacture of a number of anesthetics, was developed. By combining three different techniques, chromatography, crystallization, and racemization, high productivity was achieved. All unit operations were executed using a common solvent system, full recycling, and a minimum of solvent exchanges or removals. The target molecule was obtained with an enantiopurity of >99.5 wt %.