反应详情

A pressurized vial was charged with palladium 10 wt. % (dry basis) on activated carbon, wet (1.367 g, 1.284 mmol) while under a stream of N2 (gas). Then a solution of benzyl 1-((1S,3R,4S)-4-(ethoxycarbonyl)-3-methylcyclohexyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylate (5.631 g, 12.84 mmol) in a 1:1 mixture of EtOH (32.1 ml)/EtOAc (32.1 ml) was added into the vial. The reaction mixture atmosphere was purged with hydrogen gas (3×). The reaction was stirred vigorously under hydrogenation (35 psi) conditions for 2.5 h. The progress of the reaction was monitored by LC/MS, which suggested reaction completion LCMS (ESI) m/z 371.2 (M+Na)+. The mixture was filtered through a plug of celite and the filtrate was concentrated in-vacuo. The residue was diluted with hexane and agitated. The precipitate was collected by filtration and the solids were rinsed with hexane. This gave 1-((1S,3R,4S)-4-(ethoxycarbonyl)-3-methylcyclohexyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylic acid (3.810 g, 10.94 mmol, 85% yield) as white solid. 1H NMR (400 MHz, DMSO-d6) δ 7.91-8.21 (m, 1H), 4.47-4.69 (m, 1H), 4.01-4.16 (m, 2H), 2.56-2.70 (m, 1H), 2.12 (dt, J=4.21, 12.37 Hz, 1H), 1.93-2.06 (m, 2H), 1.71-1.90 (m, 3H), 1.19 (t, J=7.04 Hz, 3H), 0.92 (d, J=7.04 Hz, 3H); LCMS (ESI) m/z 371.2 (M+Na)+.

1. additionwas added into the vial
2. customThe reaction mixture atmosphere was purged with hydrogen gas (3×)
3. customreaction completion LCMS (ESI) m/z 371.2 (M+Na)+
4. filtrationThe mixture was filtered through a plug of celite
5. concentrationthe filtrate was concentrated in-vacuo
6. additionThe residue was diluted with hexane
7. stirringagitated
8. filtrationThe precipitate was collected by filtration
9. washthe solids were rinsed with hexane