反应详情

4-Methoxy-3-thiophenecarboxylic acid hydrazide (20 g, 0.116 mol) in 3N hydrochloric acid (200 ml), acetic acid (200 ml) and chloroform (300 ml) was cooled to 0°. Sodium nitrite (8 g, 0.116 mol) in water (25 ml) was added dropwise whilst maintaining the temperature at 0°. On completion of the addition the reaction mixture was allowed to warm up to room temperature. The organic layer was separated, washed with sodium bicarbonate solution (3 times), dried over sodium sulphate and the solvent evaporated without heat to give the title compound as a buff-coloured solid, 21.2 g.

1. temperaturewhilst maintaining the temperature at 0°
2. additionOn completion of the addition the reaction mixture
3. customThe organic layer was separated
4. washwashed with sodium bicarbonate solution (3 times)
5. dry with materialdried over sodium sulphate
6. customthe solvent evaporated
7. temperaturewithout heat