Ethanol → 4-[4-(3,5-dichloro-phenyl)-4-trifluoromethyl-3,4-dihydro-2H-pyrrol-2-yl]-2-methyl-benzoic acid ethyl ester

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Reaction Steps

To a solution of 2-(4-bromo-3-methyl-phenyl)-4-(3,5-dichloro-phenyl)-4-trifluoromethyl-3,4-dihydro-2H-pyrrole (Example 14) (7.0 g) in a mixture of ethanol (60 ml) and dimethylformamide (20 ml), was added dichloro 1,1′-bis(diphenylphosphino)ferrocene palladium(II) dichloromethane adduct (“Pd(dppf)Cl2”) (0.8 g) and sodium acetate (1.4 g) at ambient temperature. The reaction mixture was stirred in a pressure reactor in an atmosphere of carbon monoxide (6 bar) at 85° C. for 16 hours. The reaction mixture was cooled to ambient temperature, the ethanol was evaporated and aqueous sodium hydrogen carbonate (saturated) (200 ml) and ethyl acetate (250 ml) were added. The phases were separated and the organic phase was dried over sodium sulfate and concentrated. The residue was purified by chromatography on silica gel (eluent: gradient of 0-4% v/v methanol in dichloromethane) to give 4-[4-(3,5-dichloro-phenyl)-4-trifluoromethyl-3,4-dihydro-2H-pyrrol-2-yl]-2-methyl-benzoic acid ethyl ester (2.8 g). 1H-NMR (CDCl3, 400 MHz): 8.04-7.06 (m, 7H), 5.46-5.06 (m, 1H), 4.35 (m, 2H), 3.27-3.79 (m, 1H), 2.59 (m, 3H), 2.38-2.10 (m, 1H), 1.39 (m, 3H) ppm.

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