反应详情

3-Propionyl-benzonitrile (0.61 g, 3.8 mmol) was refluxed in ethanol (5.3 mL) and KOH (0.48 g, 8.5 mmol) for 2 h. The ethanol was evaporated and the residue suspended in water (5 mL) and treated with 2N HCl (3.7 mL) to pH 1-2. The slurry was extracted with ethyl acetate. The combined organic phases were washed with water and saturated sodium chloride, dried over sodium sulphate and evaporated. The residue was dissolved in methanol (3.5 mL) and treated with 97% sulfuric acid (0.26 mL). The mixture was stirred at room temperature for 16 h, then at 70° C. for 7.5 h and at 50° C. for 16 h. After evaporation of methanol, the residue was suspended in water and extracted with ethyl acetate. The combined organic phases were washed with water and saturated sodium chloride, dried over sodium sulphate and evaporated. The residue was purified by flash chromatography (heptane/ethyl acetate gradient) to yield 3-propionyl-benzoic acid methyl ester as an off-white solid (0.42 g, 56%).

1. customThe ethanol was evaporated
2. additiontreated with 2N HCl (3.7 mL) to pH 1-2
3. extractionThe slurry was extracted with ethyl acetate
4. washThe combined organic phases were washed with water and saturated sodium chloride
5. dry with materialdried over sodium sulphate
6. customevaporated
7. dissolutionThe residue was dissolved in methanol (3.5 mL)
8. additiontreated with 97% sulfuric acid (0.26 mL)
9. waitat 70° C. for 7.5 h
10. waitat 50° C. for 16 h
11. customAfter evaporation of methanol
12. extractionextracted with ethyl acetate
13. washThe combined organic phases were washed with water and saturated sodium chloride
14. dry with materialdried over sodium sulphate
15. customevaporated
16. customThe residue was purified by flash chromatography (heptane/ethyl acetate gradient)