反应详情

To a solution of 3,3,3-trifluoro-2-hydroxy-2-methyl-propionic acid methyl ester (22.94 g, 133 mmol) in CH2Cl2 (400 ml) was added rhodium(II) trifluoroacetate dimer (0.439 g, 0.667 mmol). After cooling to 0° C. a solution of 1-(3-bromo-phenyl)-2-diazo-ethanone (15.0 g, 66.7 mmol) dissolved in CH2Cl2 (100 ml) was added over a period of 2 h. The reaction mixture was concentrated and the title compound was obtained after flash-chromatography on silica gel (toluene) as a yellow oil: TLC (toluene/EtOAc 10:1): Rf=0.45; HPLC RtH5=1.352 min; 1H NMR (360 MHz, CDCl3): δ 8.15 (s, 1H), 7.94 (d, 1H), 7.76 (d, 1H), 7.40 (t, 1H), 4.87 (s, 2H), 3.89 (s, 3H), 1.72 (s, 3H); ESIMS: 386, 388 [(M+NH4)+].

1. additionwas added over a period of 2 h
2. concentrationThe reaction mixture was concentrated