反应详情

Methyl 2-benzylidene-3-acetoxypropionate [formula (IV), R1=Ph, R2=Me, R3=acetyl group, 143.9 g] obtained in Example 2 was dissolved in 400 ml of methanol, and an aqueous solution of 96.0 g (97%, 2.40 mols) of sodium hydroxide in 800 ml of water was added thereto. The resulting mixture was then stirred at room temperature for 90 minutes. After the completion of the reaction, the reaction solution was concentrated under reduced pressure, and methanol was distilled off. Subsequently, the residue was neutralized with the addition of 100 ml of water and 250 ml of 36% hydrochloric acid, and extracted with 600 ml of ethyl acetate. The resulting organic layer was washed with 300 ml of a saturated aqueous solution of sodium chloride, and insoluble matters were separated by filtration. The resulting solution was concentrated under reduced pressure. Toluene was added to the resulting residue in four divided portions in an amount of 250 ml each. The mixture was concentrated under reduced pressure, and acetic acid was removed to obtain 107.8 g of a crude product of the above title compound.

1. customAfter the completion of the reaction
2. concentrationthe reaction solution was concentrated under reduced pressure, and methanol
3. distillationwas distilled off
4. additionSubsequently, the residue was neutralized with the addition of 100 ml of water and 250 ml of 36% hydrochloric acid
5. extractionextracted with 600 ml of ethyl acetate
6. washThe resulting organic layer was washed with 300 ml of a saturated aqueous solution of sodium chloride, and insoluble matters
7. customwere separated by filtration
8. concentrationThe resulting solution was concentrated under reduced pressure
9. additionToluene was added to the resulting residue in four divided portions in an amount of 250 ml each
10. concentrationThe mixture was concentrated under reduced pressure, and acetic acid
11. customwas removed