反应详情

A solution of 2′-methylacetophenone (0.98 ml, 7.4 mmol), ethyl carbazate (0.81 g, 7.8 mmol) and p-toluenesulfonic acid monohydrate (70 mg, 0.37 mmol) in toluene (30 ml) was heated at reflux temperature with a Dean-Stark apparatus for 2 h. Solvent evaporation and flash chromatography (silica gel, hexane-ethyl acetate, 80:20) gave N′-(1-o-tolyl-ethylidene)-hydrazinecarboxylic acid ethyl ester; 1H NMR (CDCl3, 400 MHz) δ 7.72 (bs, 1H), 7.21 (m, 4H), 4.31 (q, 2H, J=7.1 Hz), 2.37 (s, 3H), 2.17 (s, 3H), 1.34 (t, 3H, J=7.1 Hz).

1. temperatureat reflux temperature with a Dean-Stark apparatus for 2 h
2. customSolvent evaporation and flash chromatography (silica gel, hexane-ethyl acetate, 80:20)