反应详情

A solution of triphenylphosphine (0.123 mL, 0.530 mmol) in dry CH2Cl2 (1.3 mL) was added dropwise via cannula to a stirred solution of 4-(2-hydroxyethoxy)-2-methoxyphenyl acetate (100 mg, 0.442 mmol) and carbon tetrabromide (0.051 mL, 0.530 mmol) in dry CH2Cl2 (3.0 mL) at 0° C. under N2. After 5 h at 0° C., the reaction mixture was concentrated in vacuo and the residue obtained was purified by flash chromatography (Biotage Horizon, 25M, Si, ˜20 mL/min, 100% hexanes for 144 mL, gradient to 50% EtOAc in hexanes over 1125 mL) to afford 4-(2-bromoethoxy)-2-methoxyphenyl acetate, as a colorless oil. Rf=0.78 (50% EtOAc/hexanes). LCMS calc.=289.1; found=288.8 (M+H)+. 1H NMR (500 MHz, CHCl3): δ 6.93 (d, J=8.7 Hz, 1 H); 6.57 (d, J=2.8 Hz, 1 H); 6.42 (dd, J=8.7, 2.8 Hz, 1 H); 4.26 (t, J=6.2 Hz, 2 H); 3.80 (s, 3 H); 3.62 (t, J=6.2 Hz, 2 H); 2.29 (s, 3 H).

1. concentrationthe reaction mixture was concentrated in vacuo
2. customthe residue obtained
3. customwas purified by flash chromatography (Biotage Horizon, 25M, Si, ˜20 mL/min, 100% hexanes for 144 mL, gradient to 50% EtOAc in hexanes over 1125 mL)