Patent ID: 9266888
Filing Date: 2016-02-23
CPC Classification: A61P,C07B,C07D

Claim Text:
1. A method of preparing an anhydrous polymorph A of the compound 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine, the method comprising: (a) dissolving 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine in absolute ethanol to provide a solution; (b) refluxing the solution to provide a hot solution and, optionally filtering the hot solution to provide a hot filtrate, (c) cooling the hot solution or the hot filtrate until crystallisation sets in, (d) diluting the cooled solution or the cooled filtrate with a solvent to provide a solvent mixture, (e) suction filtering the solvent mixture, and (f) drying the solids collected by filtration at 45° C. in vacuo to provide said anhydrous polymorph A; wherein