Patent ID: 9663497
Date: 2017-05-30
CPC Classifications: A61P,C07B,C07C,C07D,C30B

Claim:
1. A method of obtaining a purified pharmaceutically acceptable salt of a [5-(4,6-dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine, comprising: forming a hemitartrate salt of the compound of formula (2): in a low-alkyl alcohol solvent to yield a hemitartrate salt alcohol mixture; a first crystallizing out of said mixture the solid hemitartrate of formula 2.1: wherein said first crystallizing is performed once, and said solid hemitartrate of formula (2.1) that is obtained after said once performed crystallizing has a purity of at least about 98.9%; dissolving said solid hemitartrate in a low-alkyl alcohol-containing medium to yield a low-alkyl alcohol-containing hemitartrate solution; a second crystallizing out of said hemitartrate solution a re-crystallized hemitartrate of formula 2.1; dissolving said hemitartrate in water to yield an aqueous hemitartrate solution; seeding said aqueous solution with crystal seeds of the tetrahydrate of said hemitartrate; and a third crystallizing said aqueous hemitartrate solution to form the solid tetrahydrate hemitartrate of formula (3):