1108724-32-8

General procedure for the synthesis of 3-bromo-5-(1,1-difluoroethyl)pyridine from 3-acetyl-5-bromopyridine: 1-(5-bromopyridin-3-yl)ethanone (500 mg, 2.5 mmol) and bis(2-methoxyethyl)aminosulfur trifluoride (BAST, 2.2 g, 10 mmol) were dissolved in dichloromethane (8 mL) in an airtight tube at 60 C overnight. The progress of the reaction was monitored by thin layer chromatography (TLC, unfolding reagent ratio PE:EtOAc = 1:1) and after confirming the completion of the reaction, the reaction mixture was concentrated. The residue was purified by fast column chromatography (silica gel as stationary phase, eluent ratio PE:EtOAc = 1:1) to afford the target product 3-bromo-5-(1,1-difluoroethyl)pyridine (200 mg, 36% yield). Mass spectrometry (MS) analysis showed (M + 1) = 222/224.

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