反应详情

5 g of methoxy-acetic acid (55.5 mmol) were dissolved in 70 ml of dimethylformamide. 11.73 g of 1,1′-carbonyldiimidazol (72.3 mmol) were added in portions within 10 min. After 30 min. at room temperature 23 ml of pyridine were added. Then 5.84 g of 4-methyl-3-thiosemicarbazide (55.5 mmol) were added and the obtained solution was stirred at room temperature overnight, and for an additional 3 h at 100° C. The solvent was evaporated, the residue dissolved in 70 ml of saturated aqueous sodium chloride solution and 30 ml of water. The aqueous layer was extracted six times with 100 ml of ethyl acetate each, and the combined organic layers were dried over magnesium sulfate, filtered, and the solvent was evaporated to dryness to yield 17 g of the crude title compound, which was further purified by silica gel chromatography with ethyl acetate, thereby obtaining 7.1 g of the purified title compound.

1. waitfor an additional 3 h at 100° C
2. customThe solvent was evaporated
3. dissolutionthe residue dissolved in 70 ml of saturated aqueous sodium chloride solution
4. extractionThe aqueous layer was extracted six times with 100 ml of ethyl acetate each, and the combined organic layers
5. dry with materialwere dried over magnesium sulfate
6. filtrationfiltered
7. customthe solvent was evaporated to dryness