Process for the preparation of chiral 8-(-3-aminopiperidin-1-yl) xanthines

摘要

The invention relates to an improved process for preparing enantiomerically pure 8-(3-aminopiperidin-1-yl)-xanthines. The process involves reacting a compound of the formula (III) with 3-(phthalimido)piperidine or an enantiomer thereof where X is a leaving group selected from halogens and sulphonic ester acid residues, and R1 to R3 are as defined herein, to obtain a compound of the formula (II) and deprotecting the obtained compound of the formula (II) to obtain the product xanthines.