(Diethylamino)sulfur trifluoride → Tert-butyl 4-(4-bromo-1,3-thiazol-2-yl)-4-fluoropiperidine-1-carboxylate

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Reaction Steps

Diethylaminosulfur trifluoride (DAST) (0.083 mL, 0.627 mmol) was added to a 0° C. of tert-butyl 4-(4-bromothiazol-2-yl)-4-hydroxypiperidine-1-carboxylate (0.207 g, 0.570 mmol) in dichloromethane (2.8 mL). After 5 minutes, the cooling bath was removed and the reaction mixture was allowed to stir at room temperature overnight. Saturated aqueous sodium bicarbonate solution was added, and the aqueous phase was separated and extracted with dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and concentrated. The residue was purified via column chromatography on silica gel (Biotage 25 g column, gradient elution with 5-50% ethyl acetate-hexane) to afford tert-butyl 4-(4-bromothiazol-2-yl)-4-fluoropiperidine-1-carboxylate (0.163 g, 78%) as a colorless, waxy solid. MS (ESI, pos. ion) m/z 387, 389 [M+Na]+.

Provenance & Evidence