Process for the single crystallization of enatiomeric ratio's (2S,3S):(2R,3R) of substituted 1,5-benzothiazepinone
AssigneeZambon Group S.p.A.
InventorsClaudio Giordano, Dario Tentorio, Laura Russo
Life of this patent
Estimating the term…
Abstract
A purification method of intermediates for the preparation of Diltiazem which consists of the crystallization of a mixture enantiomerically enriched in (2S,3S)-2,3-dihydro-3-hydroxy-2-(4-methoxyphenyl)-1,5-benzothiazepin-4(5H) -one is described.
Claims3
A purification process of (2S,3S)-2,3-dihydro-3-hydroxy-2-(4-methoxyphenyl)-1,5-benzothiazepin-4(5H) -one consisting of the single crystallization without conversion to diastereomers of a mixture enantiomerically enriched in the (2S,3S) enantiomer of 2,3-dihydro-3-hydroxy-2-(4-methoxyphenyl)1,5-benzothiazepin-4(5H)-one, such that the enantiomeric ratio (2S,3S):(2R,3R) is at least 75:25, in an organic solvent selected from the class consisting of lower alcohols, aromatic hydrocarbons and ketones optionally in admixture with dipolar aprotic solvents.
Dependencies are inferred from the claim text.