Preparation method of esomeprazole potassium

The invention discloses a preparation method of esomeprazole potassium. The preparation method comprises the following steps: (1) putting methylbenzene into a dry reaction kettle, and introducing nitrogen into the methylbenzene until the end of centrifugation; (2) putting omeprazole sulfide, rising the temperature to 30 to 32 DG C, and putting 26 KG of D-(-)diethyl tartrate; (3) rising the temperature to 44 to 46 DEG C, and putting isopropyl titanate (IV) after stirring for 30 minutes; (4) cooling to 31 to 35 DEG C, and putting diisopropylethylamine; (5) keeping the temperature be 31 to 33 DEG C, and dropwise adding cumyl hydroperoxide within 30 minutes to 2 hours; (6) keeping the temperature be 31 to 33 DEG C for 15 minutes for reacting; checking the content of sulfide through QC (Quality Control), and monitoring whether the reaction ends or not; (7) after the end of the reaction, stirring a methanol solution of potassium hydroxide; (8) cooling to 25 to 30 DEG C and keeping for 1 hour; (9) centrifuging, thus obtaining a coarse product, and refining further.