反应详情

A mixture of 1-[4,5-(methylenedioxy)-2-(phenylmethoxy)phenyl]ethanone (5.4 g, 0.02 mol), sodium hydride (1.6 g of 60% sodium hydride, 0.04 mol) and dimethylcarbonate (18 g, 0.2 mol) was heated to 70°-75° C. for 20 minutes. After evaporating the excess dimethylcarbonate under reduced pressure, the residue was acidified with 10% HCl solution and extracted with ether. The ether solution was washed with water, dried (Na2SO4), filtered and concentrated under reduced pressure. The crude product was filtered through silica gel using chloroform as eluent to afford 5.99 g (91.3%) of methyl 4,5-(methylenedioxy)-β-oxo-2-(phenylmethoxy)benzenepropanoate mp (EtOH) 86°-86.5° C.; IR (KBr) 1750 (ester), 1652 (carbonyl) cm-1 ; NMR (CDCl3, 90 MHz) δ, 3.61 (S, 3H, CO2CH3), 3.92 (S, 2H, CH2CO2CH3), 5.11 (S, 2H, CH2Ph), 5.98 (S, 2H, OCH2O), 6.54 (S, 1H, ArH), 7.39 (S, 5H, CH2Ph), 7.41 (S, 1H, ArH). Anal. calcd. for C18H16O6 : C, 65.85; H, 4.91. Found: C, 65.92; H, 5.11.

1. temperaturewas heated to 70°-75° C. for 20 minutes
2. customAfter evaporating the excess dimethylcarbonate under reduced pressure
3. extractionextracted with ether
4. washThe ether solution was washed with water
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. filtrationThe crude product was filtered through silica gel