反应详情

The product (143.9 g) in Reference Example 2, namely 2-benzylidene-3-acetoxypropionate methyl ester, is dissolved in methanol (400 ml), followed by addition of an aqueous solution of sodium hydroxide (96.0 g; 2.40 mol; purity of 97%) in water (800 ml). The resulting mixture is stirred at ambient temperature for 90 minutes. The reaction solution is concentrated under reduced pressure to distill off methanol, followed by addition of water (100 ml) and 36% hydrochloric acid (250 ml) for adjusting the resulting mixture to neutrality and subsequent extraction into ethyl acetate (600 ml). The resulting organic phase is washed with saturated saline (300 ml). After filtering off insoluble matters, the resulting solution is concentrated under reduced pressure. To the resulting residue is added toluene (250 ml×4), and the mixture is concentrated under reduced pressure to remove acetic acid to give a crude product of the title compound (107.8 g).

1. concentrationThe reaction solution is concentrated under reduced pressure
2. distillationto distill off methanol
3. additionfollowed by addition of water (100 ml) and 36% hydrochloric acid (250 ml)
4. extractionto neutrality and subsequent extraction into ethyl acetate (600 ml)
5. washThe resulting organic phase is washed with saturated saline (300 ml)
6. filtrationAfter filtering off insoluble matters
7. concentrationthe resulting solution is concentrated under reduced pressure
8. additionTo the resulting residue is added toluene (250 ml×4)
9. concentrationthe mixture is concentrated under reduced pressure
10. customto remove acetic acid