Triethylamine → ((S)-1-(tert-butoxycarbonyl)-4,4-difluoropyrrolidin-2-yl)methyl methanesulfonate

Participants

Reaction Conditions

Reaction Steps

To a CH2Cl2 (22 ml) solution of (S)-tert-butyl 4,4-difluoro-2-(hydroxymethyl)pyrrolidine-1-carboxylate (2.65 g, 11.2 mmol) and Et3N (2.3 ml, 16.8 mmol), at 0° C., methylsulfonyl chloride (0.95 ml, 12.3 mmol) was added dropwise over ˜2 minutes, ice bath was removed after 15 minutes, and stirring was continued at room temperature for another 30 minutes. Reaction went to completion as monitored by LC-MS. The reaction mixture was cooled to 0° C. and was quenched by addition of saturated aqueous solution of NaHCO3 (˜30 ml), stifling was continued at 0° C. for 5 minutes and at room temperature for 15 minutes. Two layers were separated, aqueous layer was extracted with CH2Cl2 (˜30 ml). Organic layers were combined, washed with brine (˜25 ml), dried (Na2SO4), filtered, solvent was removed in vacuo. Compound ((S)-1-(tert-butoxycarbonyl)-4,4-difluoropyrrolidin-2-yl)methyl methanesulfonate was obtained as a very light yellow oil: 3.40 g (96% crude yield).

Provenance & Evidence