Ethyl 4-chloro-2-methylthio-5-pyrimidinecarboxylate

53554-29-3

5909-24-0

General procedure for the synthesis of ethyl 4-chloro-2-methylthiopyrimidine-5-carboxylate from ethyl 4-hydroxy-2-methylthiopyrimidine-5-carboxylate: ethyl 4-hydroxy-2-methylthiopyrimidine-5-carboxylate (30 g, 140 mmol) was placed in a three-necked flask. Thionyl chloride (20 g, 168 mmol) was added slowly. The reaction system was heated to 60 °C and maintained at this temperature for 3 hours. After completion of the reaction, the reaction solution was cooled to 0-5 °C. 100 ml of ice water was slowly added and crystallization was stirred at 0-5°C for 1-2 hours. The solid product was collected by filtration and dried under vacuum at 50 °C to give 30.1 g of white solid product. The yield was 92% and the purity was 99.8% by HPLC.