反应详情

In the manner described in Example 99, 3,3-bis(4-methylphenyl) -2-propenal (9.45 g) was reacted with (carbomethoxymethylene)triphenylphosphorane (15.3 g) in carbon tetrachloride (95 ml) for 3 days at room temperature. The solvent was removed under reduced pressure and the residue was stirred at reflux in mixture of methanol (40 mL) and 2N NaOH for 45 minutes. The cooled solution was diluted with water (300 ml), extracted with dichloromethane (3×100 mL) to remove non-acidic material, and then acidified with 6N HCI (50 ML) and extracted with dichloromethane. The dried (MgSO4) extracts were evaporated and the crude product was crystallized from 2-propanol to afford 7.5 g of (E)-5,5-bis(4-methylphenyl)-2,4-pentadienoic acid, mp 224 5°-226.5° C.

1. customThe solvent was removed under reduced pressure
2. temperatureat reflux in mixture of methanol (40 mL) and 2N NaOH for 45 minutes
3. additionThe cooled solution was diluted with water (300 ml)
4. extractionextracted with dichloromethane (3×100 mL)
5. customto remove non-acidic material
6. extractionextracted with dichloromethane
7. dry with materialThe dried (MgSO4) extracts
8. customwere evaporated
9. customthe crude product was crystallized from 2-propanol