Method for preparing (+)-(S-)-clopidogrel hydrosulfate high melting point crystal I

Preparation of (+)-(S)-chlorpyrroline hydrogen sulfate high-smelting point crystal Iis carried out by dissolving chlorpyrroline free alkali into ketone solvent, adding into concentrated sulfuric acid, eluting crystal out, adding into alcohol solvent, agitating while crystallizing, filtering, washing for filter cake by ketone solvent, pumping and vacuum drying to obtain final product. It's simple and efficient, has gentle reactive condition and can be used for industrial production.