反应详情

Microwave heat a mixture of tert-butyl 4-(2-oxo-2-(3-(trifluoromethyl)phenyl)-ethylcarbamoyl)piperidine-1-carboxylate (2.5 g, 6.09 mmol) and NH4Cl (1.68 g, 31.4 mmol) in ethanol (20 mL) at 300 W, 120° C., and 200 PSI for 16 h in a CEM Discover microwave apparatus. Cool the mixture to room temperature. Repeat the procedure with a second portion of tert-butyl 4-(2-oxo-2-(3-(trifluoromethyl)phenyl)ethylcarbamoyl)-piperidine-1-carboxylate (2.35 g, 5.67 mmol) and NH4Cl (1.8 g, 33.6 mmol) in ethanol (20 mL) utilizing the same microwave and heating program. Cool the mixture to room temperature. Repeat the above procedure with a third portion of tert-butyl 4-(2-oxo-2-(3-(trifluoromethyl)phenyl)ethylcarbamoyl)piperidine-1-carboxylate (2.0 g, 4.82 mmol) and NH4Cl (1.34 mg, 25.0 mmol) in ethanol (15 mL) at 300 W, 160° C., and 200 PSI for 12 h in a microwave apparatus. Cool the mixture to room temperature. Combine the batches, adsorb onto silica gel, and concentrate in vacuo. Purify the residue by silica gel chromatography (120 g RediSep column, eluting with a gradient of 0% through 100% CMA:methylene chloride, 3 L) to provide 4-(4-(3-(trifluoromethyl)phenyl)-1H-imidazol-2-yl)piperidine (3.40 g, 75%).

1. temperatureMicrowave heat
2. temperatureheating program
3. temperatureCool the mixture to room temperature
4. temperatureCool the mixture to room temperature
5. concentrationconcentrate in vacuo
6. customPurify the residue by silica gel chromatography (120 g RediSep column
7. washeluting with a gradient of 0% through 100% CMA