Acetic Anhydride → 2-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-N-[5-(5-methyl-[1,2,4]oxadiazol-3-yl)-pyrazin-2-yl]-propionamide

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-N-[5-(N-hydroxycarbamimidoyl)-pyrazin-2-yl]-propionamide (197.0 mg, 0.423 mmol) and acetic anhydride (970 μL, 10.281 mmol) was placed into a one-dram glass vial. The vial was tightly sealed, and the reaction was stirred at 120° C. for 3.5 h. The reaction was diluted with ethyl acetate (75 mL) and washed with a saturated aqueous sodium bicarbonate solution (50 mL) and a saturated aqueous sodium chloride solution (50 mL). The combined aqueous layers were back-extracted with ethyl acetate (50 mL). The resulting combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo. Biotage chromatography (FLASH 40L, Silica, 1/1 ethyl acetate/hexanes) afforded 2-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-N-[5-(5-methyl-[1,2,4]oxadiazol-3-yl)-pyrazin-2-yl]-propionamide (43.8 mg, 21%) as a white foam; mp 101.9–104.8° C. (foam to gel); (ES)+-HRMS m/e calcd for C22H24ClN5O4S (M+H)+ 490.1311, found 490.1315.

Provenance & Evidence