Details for Patent: 9,751,855

Title:	Process for the preparation of chiral 8-(3-aminopiperidin-1-yl)-xanthines
Abstract:	The invention relates to an improved process for preparing enantiomerically pure 8-(3-aminopiperidin-1-yl)-xanthines.
Inventor(s):	Pfrengle; Waldemar (Biberach an der Riss, DE), Pachur; Thorsten (Biberach an der Riss, DE), Nicola; Thomas (Mainz, DE), Duran; Adil (Biberach an der Riss, DE)
Assignee:	Boehringer Ingelheim International GmbH (Ingelheim am Rhein, DE)
Filing Date:	Jan 25, 2017
Application Number:	15/414,694
Claims:	1. A process for preparing (R)-3-(phthalimido)piperidine, comprising: reacting rac-3-aminopiperidine with phthalic anhydride; and precipitating (R)-3-(phthalimido)piperidine by adding D-tartaric acid. 2. A process for preparing (S)-3-(phthalimido)piperidine, comprising: reacting rac-3-aminopiperidine with phthalic anhydride; precipitating (S)-3-(phthalimido)piperidine by adding L-tartaric acid. 3. A process for preparing (R)-3-(phthalimido)piperidine and (S)-3-(phthalimido)piperidine, comprising: reacting rac-3-aminopiperidine with phthalic anhydride; and precipitating (R)-3-(phthalimido)piperidine by adding D-tartaric acid; and precipitating (S)-3-(phthalimido)piperidine by adding L-tartaric acid.