Methanesulfinic acid → 2(r)-(3-Chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-n-(5-methanesulfonylmethyl-pyrazin-2-yl)-propionamide

Participants

Reaction Conditions

Reaction Steps

A solution of N-(5-bromomethyl-pyrazin-2-yl)-2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-propionamide (prepared as in Example 30, 102.2 mg, 0.20 mmol) in acetone (1 mL) was cooled to 0° C. and then treated with the sodium salt of methanesulfinic acid (31.8 mg, 0.30 mmol). The reaction stirred at 0° C. for 1 h and then at 25° C. for 4 h 20 min. A second aliquot of the sodium salt of methanesulfinic acid (24.0 mg, 0.24 mmol) was added, and the reaction was stirred at 25° C. overnight. The reaction was then concentrated in vacuo. The residue was diluted with ethyl acetate (50 mL), washed with water (2×25 mL) and a saturated aqueous sodium chloride solution (25 mL), dried over sodium sulfate, filtered, and concentrated in vacuo. Biotage chromatography (FLASH 40S, Silica, 1/1 ethyl acetate/hexanes) afforded 2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-N-(5-methanesulfonylmethyl-pyrazin-2-yl)-propionamide (74.9 mg, 73%) as a white foam: mp 91–95° C. (foam to gel); (ES)+-HRMS m/e calcd for C21H26ClN3O5S2 (M+H)+ 500.1075, found 500.1080.

Provenance & Evidence