Abstract: Provided is a method for purifying ropinirole hydrochloride (4-2-di-n-propylaminoethyl-1,3-dihydro-2H-indole-2-ketohydrochloride). The method comprises: adding ropinirole hydrochloride containing a monopropyl impurity A into water, adding organic solvent, stirring and dissolving at room temperature, adding alkali, stirring, standing, demixing, and removing an aqueous layer; optionally, drying the organic layer by using anhydrous magnesium sulfate, and filtering; and adding acyl chloride or acid anhydride into the organic layer, stirring, concentrating the organic layer to be dry, adding an organic solvent into the obtained oily matter, adding concentrated hydrochloric acid, and stirring, so as to obtain the ropinirole hydrochloride. By using the method, the impurity A in the ropinirole hydrochloride can be effectively removed, and the ropinirole hydrochloride can be obtained with a high yield and a high purity, so that the impurity A is controlled and the purity of the product reaches a medicinal standard.

Abstract: A method for preparing a lisinopril intermediate is provided. The method includes: treating (R)-hydroxy-4-phenylbutyrate with sulfonyl chloride in an organic solvent in the presence of a base to obtain a solution of sulfonate; reacting the obtained solution with a salt of trifluoroacetyl lysine; and obtaining a N2-[1-(S)-alkoxycarbonyl-3-phenylpropyl]-N6-trifluoroacetyl-L-lysine by separating after the reaction is completed. The method provided has a shorter synthesis route, is easy to operate, has a low cost, and is suitable for industrial production.

Abstract: The present invention relates to a method for preparing a citalopram diol represented by formula IV, comprising the following steps: in the existence of an auxiliary reagent of metal salt, allowing 5-cyanophthalide to sequentially subjected to Grignard addition reactions with p-fluorophenyl magnesium halide and N, N-dimethylaminopropyl magnesium halide in an organic solvent; and after the reactions are completed, performing hydrolysis and separation to obtain citalopram diol represented by formula IV. In the present invention, by adding an auxiliary reagent of metal salt, the activity and the selectivity of the Grignard reactions are remarkably improved, and the reaction yield is obviously enhanced.