Methanesulfonyl chloride → HCID 89924352, compound

Participants

Reaction Steps

5-Bromo-1-methyl-1H-pyrazol-3-amine (500 mg, 2.84 mmol) and DIPEA (2.47 mL, 14.2 mmol) were stirred in anhydrous 1,2-dichloroethane (8 mL) at room temperature, then mesyl chloride (550 μL, 7.1 mmol) in 1,2-dichloroethane (1.5 mL) was added dropwise. The mixture was stirred at room temperature for 3 h, then partitioned between DCM and water. The organic phases were separated and washed with brine, then dried over sodium sulfate and concentrated. To the resulting orange/brown solid was added 1M tetrabutylammonium fluoride in THF (10.5 mL) and the mixture was heated at reflux for 4 h. The reaction mixture was concentrated and diluted with DCM (40 mL), then washed with water (4×25 mL), followed by brine (25 mL). The organic layers were dried over sodium sulfate and concentrated under vacuum. The residue was purified by FCC, eluting with 35-50% EtOAc in heptane followed by 5-10% MeOH in DCM, to afford the title compound (388 mg, 54%) as a white solid. δH (250 MHz, CDCl3) 6.33 (s, 1H), 3.85 (s, 3H), 3.02 (s, 3H).

Provenance & Evidence