Crystalline form of (s)-1-phenylethylammonium (r)-diphenylmethanesulphinyl-acetate
AssigneeDipharma Francis S.R.L.
InventorsGiuseppe Barreca, Pietro Allegrini, Gabriele Razzetti
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Abstract
Novel crystalline hydrate form of (S)-1-phenylethylammonium (R)-diphenyl-methanesulphinyl-acetate and its use in a process for the preparation of (R)-benzhydrylsulphinylacetamide.
Claims14
(S)-1-phenylethylammonium (R)-diphenyl-methanesulphinyl-acetate, in crystalline hydrate form.
A process for preparing (R)-modafinil having an enantiomeric purity equal to or higher than 99%, comprising reacting (±)-benzhydrylsulphinylacetic acid with (S)-1-phenylethylamine, converting the resulting salt (S)-1-phenylethylammonium (R)-diphenyl-methanesulphinyl-acetate to (R)-benzhydrylsulphinylacetic acid, and subjecting the resulting (R)-benzhydrylsulphinylacetic acid to amidation reaction with ammonia, characterized in that:
- compound (S)-1-phenylethylammonium (R)-diphenyl-methanesulphinyl-acetate, is obtained in crystalline hydrate form, by a process comprising:
- dispersing (S)-1-phenylethylamine, (±)-diphenyl-methanesulphinyl-acetic acid and triethylamine in water;
- heating said dispersion to dissolve the reagents;
- cooling the solution to precipitate (S)-1-phenylethylammonium (R)-diphenyl-methanesulphinyl-acetate in crystalline form;
- and
- recovering the resulting solid.
Dependencies are inferred from the claim text.