反应详情

3-Chlorocarbonyl-propionic acid methyl ester (4.4 g, 29 mmol) is added dropwise to a stirred suspension of semicarbazide (4.0 g, 44 mmol) in THF (25 ml) at 0° C. After stirring at room temperature for 1 hour, the solvent is removed to give a white solid. Toluene (30 ml) is added followed by dropwise addition of methane sulfonic acid (3.37 ml, 52 mmol) then the reaction is heated at 70° C. for 3 hours. The mixture is concentrated in vacuo and methanol (30 ml) is added. Aqueous ammonia is then added with stirring until a basic mixture is obtained. The solvents are removed and the residue is purified by chromatography on silica eluting with chloroform:methanol (10:1) to give the titled product.

1. customthe solvent is removed
2. customto give a white solid
3. temperaturethe reaction is heated at 70° C. for 3 hours
4. concentrationThe mixture is concentrated in vacuo and methanol (30 ml)
5. additionis added
6. additionAqueous ammonia is then added
7. stirringwith stirring until a basic mixture
8. customis obtained
9. customThe solvents are removed
10. customthe residue is purified by chromatography on silica eluting with chloroform:methanol (10:1)