反应详情

A solution of 5-(2-hydroxyethyl) benzofurazan (1.0 g, 6.1 mmol) and carbon tetrabromide (2.6 g, 7.9 mmol) in methylene chloride (10 ml) was cooled to 0° C. A solution of triphenylphosphine (1.9 g, 7.3 mmol) in methylene chloride (10 ml) was added dropwise and the reaction was stirred for 5 minutes. Solvent evaporation and flash chromatography (silica gel, ethyl acetate-hexane, 5/95) gave 5-(2-bromoethyl)benzofurazan (1.2 g, 86%); 1H NMR (CDCl3) δ3.32(t,2H), 3.69(t,2H), 7.32(d,1H), 7.69(s,1H), 7.84(d,1H).

1. customSolvent evaporation and flash chromatography (silica gel, ethyl acetate-hexane, 5/95)