Preparation method of atorvastatin calcium intermediate

The invention relates to a preparation method of an atorvastatin calcium intermediate. The preparation method of the atorvastatin calcium intermediate has the advantages of increase of the yield of the atorvastatin calcium intermediate, simple post-treatment process, simplified operating flow, production period shortening, reduction of the consumption of an organic solvent, reduction of the production cost, and reduction of the danger during the production operation. The method comprises the following steps: 1, carrying out a reaction on amine ester and dione used as initial raw materials in a mixed solvent, wherein the mixed solvent comprises n-heptane and tetrahydrofuran according to a volume ratio of 1:(1-3), and 5-8 ml of the mixed solvent is added to every gram of the amine ester; 2, concentrating a reaction solution obtained in step 1 to remove the mixed solvent to obtain a crude atorvastatin calcium intermediate; and 3, adding a crystallization solvent 1 ethanol to the product obtained in step 2, disso