反应详情

In a flame-dried flask was added under argon Mg (0.58 g, 0.024 mol), a few crystals of I2 and dry THF (10 ml). A solution of 6-bromo-5-(phenylmethoxy)-1,3-benzodioxole (6.14 g, 0.02 mol) in dry THF (15 ml) was added dropwise under reflux. Heating was continued for 3 hours. The Grignard reagent was added over 1.5 h to a solution of freshly distilled CH3COCl (7 ml) in dry THF (20 ml) held at -78° C. The stirred reaction mixture was allowed to warm to room temperature overnight, poured into 2N-NH4Cl (100 ml) solution and extracted with chloroform (3×50 ml). The organic layer was washed with 10% NaOH and brine, and dried (MgSO4) and concentrated under reduced pressure. The residue was subjected to flash chromatography (silica gel) using petroleum ether--CHCl3 (2:1) as eluent affording 3.87 g (71.6%) of 1-[4,5-(methylenedioxy)-2-(phenylmethoxy)phenyl]ethanone mp (EtOH) 116.5°-117° C.; IR(KBr) 1652 (carbonyl) cm-1 ; NMR (CDCl3, 90 MHz) δ 2.55 (S, 3H, CH3), 5.11 (S, 2H, CH2Ph), 5.98 (S, 2H, OCH2O), 6.58 (S, 1H, ArH), 7.34 (S, 1H, ArH), 7.40 (S, 5H, CH2Ph). Anal. calcd. for C16H14O4 : C, 71.10; H, 5.22. Found: C, 70.96; H, 5.29.

1. additionIn a flame-dried flask was added under argon Mg (0.58 g, 0.024 mol)
2. temperatureunder reflux
3. temperatureHeating
4. customheld at -78° C
5. customThe stirred reaction mixture
6. extractionextracted with chloroform (3×50 ml)
7. washThe organic layer was washed with 10% NaOH and brine
8. dry with materialdried (MgSO4)
9. concentrationconcentrated under reduced pressure