5-Bromo-2-chlorobenzoyl Chloride is an intermediate in the synthesis of labelled and unlabelled isotopes of glucuronide metabolites of dapagliflozin. It also functions as an intermediate in the synthesis of dapagliflozin, a potent and selective hSGLT2 inhibitor.
Step 1. 5-Bromo-2-chlorobenzoic acid (100 g, 0.43 mol) was dissolved in 500 mL of dichloromethane and 1 g of pyridine was added as a catalyst. Thionyl chloride (60.5 g, 0.51 mol) was added slowly and dropwise at room temperature, followed by heating the reaction mixture to 40 °C and refluxing for 3.5 hours. The reaction progress was monitored by thin layer chromatography (TLC). Upon completion of the reaction, dichloromethane was removed by distillation under reduced pressure to afford 104 g of 5-bromo-2-chlorobenzoyl chloride (yield: 97%), which can be used directly in the next step of the reaction without further purification.
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