反应详情

51 g. of Methyl 4-acetylamino-5-chloro-2-hydroxybenzoate and 36.8 g. of anhydrous potassium carbonate were suspended in 350 ml. of N,N-dimethylformamide. To the suspension was added 55 g. of α-bromo-γ-butyrolactone, and the mixture was stirred at 60° C. for 12 hours. The solvent was evaporated off under reduced pressure. The residue was diluted with water and extracted with ethyl acetate. The extract was washed with water, dried and concentrated to remove the solvent. The residue was dissolved in chloroform, and subjected to column chromatography on silica gel, using chloroform as the eluent. The product was recrystallized from methanol. By the above procedure there was obtained α-[(5-acetylamino-4-chloro-2-methoxycarbonylphenyl)oxy]-γ-butyrolactone as pale yellow prisms, m.p. 118°-119° C.

1. additionTo the suspension was added 55 g
2. customThe solvent was evaporated off under reduced pressure
3. additionThe residue was diluted with water
4. extractionextracted with ethyl acetate
5. washThe extract was washed with water
6. customdried
7. concentrationconcentrated
8. customto remove the solvent
9. dissolutionThe residue was dissolved in chloroform
10. customThe product was recrystallized from methanol