(Diethylamino)sulfur trifluoride → Tert-butyl 1-fluoromethylcyclopropylsulfonylcarbamate

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Reaction Steps

A solution of tert-butyl 1-hydroxymethylcyclopropylsulfonylcarbamate (26.0 g, 103 mmol) in DCM (300 mL) was cooled to −78° C. To this solution was added diethylaminosulfur trifluoride (“DAST”, 41.0 mL, 310 mmol). The reaction mass was stirred at the same temperature for 30 min. The reaction mass was quenched with aqueous 1N NaOH solution. The organic layer was discarded and the aqueous layer was acidified to pH˜2 by using aq. 1.5 N HCl solution. The aqueous solution was extracted with DCM (50 mL×4). The combined organic layers were dried over anhydrous sodium sulfate; filtered; then concentrated to afford desired tert-butyl(1-(fluoromethyl)cyclopropyl)sulfonylcarbamate (19 g, 72%) as gummy solid. 1H NMR (400 MHz, DMSO-d6): δ ppm 11.25 (sb, 1H), 4.75 (s, 1H), 4.63 (s, 1H), 1.44 (s, 9H), 1.28 (m, 2H), 1.07 (m, 2H). 19F NMR: −211.7 (1F).

Provenance & Evidence