Methyl cyanoacetate → 2-Cyano-3-methyl-4-oxo-4-(2-trifluoromethyl-phenyl)-butyric acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of 2′-trifluoromethyl-propiophenone (10 g, 48 mmol) in carbon tetrachloride (50 ml) was added a solution of bromine (2.72 mL, 52.8 mmol) in carbon tetrachloride (20 mL) dropwise. After the addition was complete, stirring was continued for another 2 h. The solution was washed with satd NaHCO3 and water, dried (anhyd Na2SO4) and concentrated under reduced pressure to give 2-bromo-1-(2-trifluoromethyl-phenyl)-propan-1-one as an oil (12.8 g, 95%), which was used in the next step without purification. 1H-NMR (CDCl3): δ 7.73 (m, 2H), 7.58-7.67 (m, 2H), 4.96 (q, 1H), 1.90 (d, 3H). To a solution of 2′-trifluoromethyl-propiophenone (10 g, 48 mmol) in carbon tetrachloride (50 ml) was added a solution of bromine (2.72 mL, 52.8 mmol) in carbon tetrachloride (20 m To a suspension of NaH (60%, 2.88 g, 72 mmol) in anhyd THF (200 mL) was added methyl cyanoacetate (4.5 mL, 50 mmol). After this mixture was stirred for 3 h at 20° C., a solution of 2-bromo-1-(2-trifluoromethyl-phenyl)-propan-1-one (13.5 g, 48 mmol) was added and the mixture was stirred overnight at 20° C. The mixture was quenched with water and the organic layer was separated. The aqueous layer was extracted with EtOAc. The combined extracts were washed with brine, dried (anhyd Na2SO4) and concentrated under reduced pressure to afford the title compound as an oil (13.3 g, 93%), which was used in the next step without purification. MS (ES): 300 (MH+).

Provenance & Evidence