Hydrochloric Acid → N-benzothiazol-2-yl-3-cyclopentyl-2-(4-methanesulfonyl-3-nitro-phenyl)-propionamide

Participants

Reaction Steps

A solution of 3-cyclopentyl-2-(4-methanesulfonyl-3-nitrophenyl)-propionic acid (50 mg, 0.15 mmol), triethylamine (0.060 mL, 0.44 mmol), benzotriazol-1-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate (98 mg, 0.22 mmol), and 2-aminobenzothiazole (33 mg, 0.22 mmol) in N,N-dimethylformamide (3 mL) was stirred at 25° C. for 3 h. The reaction mixture was then diluted with water (25 mL), a 1N aqueous hydrochloric acid solution (5 mL), and ethyl acetate (25 mL). The layers were separated. The resulting organic layer was washed with a saturated aqueous sodium chloride solution (1×25 mL), dried over magnesium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 2/1 hexanes/ethyl acetate) afforded N-benzothiazol-2-yl-3-cyclopentyl-2-(4-methanesulfonyl-3-nitro-phenyl)-propionamide (31 mg, 45%) as a pale yellow foam: mp 108-113° C. (foam to gel); EI-HRMS m/e calcd for C22H23N3O5S2 (M+) 473.1079, found 473.1077.

Provenance & Evidence