反应详情

Alternatively, the title compound can be obtained by carrying out the following experiment: To a vigorously stirred solution of 4-[(R)-3-Cyano-3-(3,5-dichloro-phenyl)-4,4,4-trifluoro-butyryl]-2-methyl-benzoic acid tert-butyl ester (150 mg) in ethanol (9 mL) was added Raney Nickel (1.44 g, 50% suspension in water, previously washed with dry ethanol) and the reaction was stirred at room temperature under hydrogen (1 atm) for 2 hours then under arong overnight. Then the solution was filtered over celite, and the resulting filtrate was concentrated in vacuo to give the title compound (138 mg) as a pale yellow oil. The crude product was purified by flash chromatography (15% dichloromethane in ethyl acetate) to afford 4-[(R)-4-(3,5-dichloro-phenyl)-4-trifluoromethyl-4,5-dihydro-3H-pyrrol-2-yl]-2-methyl-benzoic acid tert-butyl ester as a pale yellow oil (0.070 g). Chiral HPLC analysis (Chiralpack IA, Heptane:2-propanol:diethylamine=90:10:0.1, 1 ml/min, retention time 5.93 minutes (major enantiomer), 8.57 minutes (minor enantiomer).

1. washpreviously washed with dry ethanol) and the reaction
2. waitunder arong overnight
3. filtrationThen the solution was filtered over celite
4. concentrationthe resulting filtrate was concentrated in vacuo