4-Methylpyrazole → HCID 44190586, compound

Participants

Reaction Conditions

Reaction Steps

Trifluoroacetic acid (40.0 uL, 0.519 mmol) was added to a solution of 4-methylpyrazole (0.901 g, 11.0 mmol) in dihydropyran (2.0 mL, 22 mmol). The reaction mixture was stirred at 90° C. for 20 hours. The mixture was cooled to room temperature, and then quenched with Sodium hydride (92 mg, 2.3 mmol). After stirring at room temperature for 10 minutes more, the solvent was removed under vacuum. The residue was suspended in dichloromethane, and passed through a short plug of silica, rinsed with dichloromethane. The filtrate was evaporated in vacuo to yield 1.5213 g (83%) of 4-methyl-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole. LCMS (ESI): M+H=167.4; 1H NMR (400 MHz, DMSO-d6) δ 7.60 (s, 1H), 7.27 (s, 1H), 5.29 (d, J=9.9 Hz, 1H), 3.89 (d, J=11.2 Hz, 1H), 3.64-3.51 (m, 1H), 2.00 (overlapping s and m, 4H), 1.88 (dd, J=27.1, 13.0 Hz, 1H), 1.64 (m, 1H), 1.51 (m, 2H).

Provenance & Evidence