反应详情

3-(2-Aminobenzoyl)propionic acid (26.7 g) and concentrated sulphuric acid (25 cc) in absolute ethanol (250 cc) are stirred for 17 hours at room temperature (approximately 20° C.). The ethanol is evaporated off under reduced pressure, water (200 cc) and ethyl acetate (200 cc) are added and potassium carbonate is added until the pH is 8. The mixture is filtered, and the aqueous phase decanted and re-extracted with ethyl acetate (2×100 cc). The organic phase is dried over magnesium sulphate, filtered and evaporated to dryness under reduced pressure. Ethyl 3-(2-aminobenzoyl)propionate (24.8 g) is obtained in the form of an oil. The proton NMR spectrum in deuterated chloroform shows the following characteristics:

1. customThe ethanol is evaporated off under reduced pressure, water (200 cc) and ethyl acetate (200 cc)
2. additionare added
3. additionpotassium carbonate is added until the pH is 8
4. filtrationThe mixture is filtered
5. customthe aqueous phase decanted
6. extractionre-extracted with ethyl acetate (2×100 cc)
7. dry with materialThe organic phase is dried over magnesium sulphate
8. filtrationfiltered
9. customevaporated to dryness under reduced pressure