Oxalyl chloride → N-(4-benzoylpyrrolidino)-1-(4-methoxyphenyl)-3-(methylthio)-1H-pyrazole-5-carboxamide

Participants

Reaction Steps

Oxalyl chloride (140 μl, 1.6 mmol) and dry DMF (2 drops) were added at room temperature to 1-(4-methoxyphenyl)-3-methylthio-1H-pyrazole-5-carboxylic acid (275 mg, 1.0 mmol) in dry CH2Cl2 (8 mL) and stirred for 100 minutes under N2. The resulting solution was evaporated and placed briefly under high vacuum before redissolving in CH2Cl2 (8 mL). (4-aminobenzoyl)pyrrolidine (198 mg, 1.0 mmol) was added, followed by 4-dimethylaminopyridine (190 mg, 1.6 mmol). The resulting mixture was stirred at room temperature for 17 hours, diluted with CH2Cl2, and extracted with H2O. The aqueous extract was extracted with CH2Cl2, the combined organic extracts were extracted with brine. The organic layer was dried over Na2SO4, filtered, and evaporated. The crude product was chromatographed on silica gel (75-100% EtOAc/hexanes) to yield the desired product (464 mg, 100%). 1H NMR (CDCl3): δ7.91 (bs, 1H), 7.44 (s, 4H), 7.39 (d, 2H, J=8.8), 6.97 (d, 2H, J=8.8), 6.83 (s, 1H), 3.84 (s, 3H), 3.62 (t, 2H, J=6.6), 3.42 (t, 2H, J=6.6), 2.57 (s, 3H), 1.91 (m, 4H).

Provenance & Evidence