Patent ID: 7557218

Claim:
A process for isolating crystals of an optionally substituted 2-(2-pyridinyl)methylthio-1H-benzimidazole hydrate of formula I: in which R 1 , R 2 and R 3 , identical or different, denote hydrogen, a C1-C8 alkyl, C3-C8 cycloalkyl, C2-C8 fluoroalkyl or C1-C8 alkoxy moiety, R 4 and R 5 , identical or different, denote hydrogen, a C1-C8 alkyl, C3-C8 cycloalkyl, CH 2 —C3-C8 cycloalkyl, C1-C8 alkoxycarbonyl, C1-C8 alkoxy, C1-C8 fluoroalkoxy, CF 3 —, C2-C8 fluoroalkyl or C(O)O—C1-C8 alkyl moiety, and R 6 denotes hydrogen or a C1-C2 alkyl moiety and x means 0.5-2, said process comprising: a) providing a reaction medium comprising (i) the free base of the structural formula: wherein R 1 -R 6 have the meaning given above; and (ii) a water-soluble, organic solvent; b) at most partially removing the water-soluble, organic solvent present in the reaction medium; c) adding water to the reaction medium at a temperature of below 40° C. in quantities of at least 55 wt. % of water, relative to the weight of the reaction medium, to form hydrates; d) separating the hydrates formed as crystals; and e) optionally purifying the crystals.