反应详情

温度

35 °C

112.5 ml (116 g, 2.312 mol) of hydrazine hydrate were added slowly to a solution of 90 g (0.489 mol) of methyl (3-methylthiophen-2-yl)oxoacetate in 260 ml of diethylene glycol, and the mixture was heated at reflux for 30 min. After cooling to 30-40° C., 82 g (1.246 mol) of potassium hydroxide were added a little at a time, which was associated with a temperature increase to 70-80° C. with simultaneous evolution of nitrogen. The mixture was then slowly heated to reflux and stirred at this temperature for a total of 5 h. After cooling to room temperature, the mixture was poured into 2 l of water, adjusted to pH=1 using 250 ml of semiconcentrated hydrochloric acid and extracted with ethyl acetate. Drying of the organic phase over magnesium sulphate, filtration and removal of the solvent gave 50 g of (3-methylthiophen-2-yl)acetic acid. Yield: 66%. 1H-NMR (DMSO): δ=7.25 (d, 1H), 6.84 (d, 2H), 3.67 (s, 2H), 2.11 (s, 3H).

1. temperaturethe mixture was heated
2. temperatureat reflux for 30 min
3. temperatureincrease to 70-80° C. with simultaneous evolution of nitrogen
4. temperatureThe mixture was then slowly heated
5. temperatureto reflux
6. temperatureAfter cooling to room temperature
7. extractionextracted with ethyl acetate
8. dry with materialDrying of the organic phase over magnesium sulphate, filtration and removal of the solvent