反应详情

温度

90 °C

To a solution of ethyl 4-methyl-3-(trifluoromethyl)benzoate (for a preparation see Intermediate 19)(2.25 g, 9.69 mmol) in carbon tetrachloride (25 ml) was added NBS (1.90 g, 10.7 mmol, Aldrich) and then benzyl peroxide (0.030 g, 0.124 mmol, Acros). The suspension was heated overnight at 90° C. under nitrogen. The suspension was filtered through a hydrophobic frit and the residue washed with carbon tetrachloride (10 ml). The filtrate was concentrated in vacuo to leave a mobile colourless oil (3.1 g). The residue was loaded in dichloromethane and purified on silica (100 g×2) using 0-100% dichloromethane-cyclohexane. The appropriate fractions were combined and evaporated in vacuo to give the title compound as a white crystalline solid (1.6 g). LCMS: (System 4) MH+=312, tRET=3.32 min

1. filtrationThe suspension was filtered through a hydrophobic frit
2. washthe residue washed with carbon tetrachloride (10 ml)
3. concentrationThe filtrate was concentrated in vacuo