Benzimidazole compound crystal
A novel crystal of (R)-2-[[[3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridinyl]methyl]sulfinyl]-1H-benzimidazole or a salt thereof of the present invention is useful for an excellent antiulcer agent.
1. A method for producing an amorphous of (R)-2-[[[3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridinyl]methyl]sulfinyl]-1H-benzimidazole or salt thereof, which comprises:
subjecting a racemate of a compound of 2-[[[3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridinyl]methyl]sulfinyl]-1H-benzimidazole to an optical resolution so that an R-enantiomer of the compound is obtained;
adding a solvent comprising ethanol to the obtained R-enantiomer of the compound so that the R-enantiomer of the compound dissolves in the solvent and an R-enantiomer solution is formed;
optionally concentrating the R-enantiomer solution so as to form a concentrate;
further adding hexane to the R-enantiomer solution or the concentrate; and
evaporating the resulting solution to dryness.
2. A method according to claim 1 , wherein the optical resolution is carried out by using a chiral column.