反应详情

40 g. of potassium 5-chloro-2-sulfothiophene-3-carboxylate are dissolved in 24 g. of caustic potash dissolved in 400 ml. of water, stirred with 4 g. of activated charcoal, and filtered. 2 g. of palladium/activated charcoal (10% Pd) are then added and the mixture is hydrogenated at room temperature and at an initial pressure of approximately 1 atmosphere until no more hydrogen is taken up. The catalyst is removed by filtration. The filtrate is concentrated by evaporation to 35 ml., and acidified with concentrated HCl to a pH of 1. The precipitate that separates out is redissolved by heating. The resulting solution is cooled to 5°, and the precipitated product is suction filtered without rewashing and dried in vacuo to constant weight, and potassium 2-sulfothiophene-3-carboxylate is obtained.

1. filtrationof activated charcoal, and filtered
2. additionof palladium/activated charcoal (10% Pd) are then added
3. customis hydrogenated at room temperature
4. customThe catalyst is removed by filtration
5. concentrationThe filtrate is concentrated by evaporation to 35 ml
6. dissolutionThe precipitate that separates out is redissolved
7. temperatureby heating
8. temperatureThe resulting solution is cooled to 5°
9. filtrationfiltered without rewashing
10. customdried in vacuo to constant weight