反应详情

To a solution of 2-cyano-3-methyl-4-oxo-4-(2-trifluoromethyl-phenyl)-butyric acid methyl ester (13.27 g, 44.4 mmol) in formic acid (100 mL) was added freshly prepared Raney nickel [Al—Ni (1:1), 117 g] and the mixture was heated to reflux with stirring for 2 h. After cooling, the catalyst was removed by filtration and washed with ethanol. The combined filtrates were concentrated to give an oil, which was re-dissolved in DCM and filtered to remove residual solids. Evaporation of solvent gave 4-methyl-5-(2-trifluoromethyl-phenyl)-2,3-dihydro-1H-pyrrole-3-carboxylic acid methyl ester as an oil (10 g, 79%), which was used in the next step without purification. MS (ES): 286 (MH+).

1. temperaturethe mixture was heated
2. temperatureto reflux
3. temperatureAfter cooling
4. customthe catalyst was removed by filtration
5. washwashed with ethanol
6. concentrationThe combined filtrates were concentrated
7. customto give an oil, which
8. filtrationfiltered
9. customto remove residual solids
10. customEvaporation of solvent