反应详情

Oxalyl chloride (5.8 mL, 66.6 mmol) was added slowly to a solution of α,α-dimethyl-3,5-bis(trifluoromethyl)benzeneacetic acid (Description 6, 10 g, 33.3 mmol) and dimethylformamide (1 drop) in dichloromethane (100 mL) and. the mixture was stirred at room temperature for 24 hours. The solvent was evaporated under reduced pressure and the residue was dissolved in dichloromethane (20 mL) and added slowly to a solution of 4-oxo-1-phenylcyclohexylamine hydrochloride (Description 18, 8.2 g, 43.4 mmol) and pyridine (5.7 mL, 66.3 mmol) in dichloromethane (100 mL). The mixture was stirred at room temperature for 24 hours, then hydrochloric acid (2M, 100 mL) was added. The layers were separated and the aqueous layer was extracted with dichloromethane. The combined organic fractions were dried (MgSO4) and the solvent was evaporated under reduced pressure. The residue was purified by flash column chromatograph on silica gel, eluting with isohexane:EtOAc (75:25), to give the title compound as a colorless solid (6.5 g, 41%). 1H NMR (400 MHz, CDCl3) δ 7.83 (1H, s), 7.77 (2H, s), 7.35–7.26 (5H, m), 5.44 (1H, s), 2.70–2.66 (2H, m), 2.40–2.30 (6H, m), and 1.62 (6H, s).

1. customThe solvent was evaporated under reduced pressure
2. dissolutionthe residue was dissolved in dichloromethane (20 mL)
3. stirringThe mixture was stirred at room temperature for 24 hours
4. customThe layers were separated
5. extractionthe aqueous layer was extracted with dichloromethane
6. dry with materialThe combined organic fractions were dried (MgSO4)
7. customthe solvent was evaporated under reduced pressure
8. customThe residue was purified by flash column chromatograph on silica gel
9. washeluting with isohexane:EtOAc (75:25)