反应详情

Lithium aluminum hydride (6.45 g, 170 mmol) was added to a 250 mL round-bottom flask equipped with a magnetic stirrer bar and a septum. The flask was dried under vacuum and then filled with nitrogen. Anhydrous ether (50 mL) was first injected into the flask. Subsequently, a solution of 3-bromo-4-methylacetophenone (38 g, 180 mmol) in anhydrous ether (50 mL) was injected into the flask dropwise. The reaction mixture was stirred until no more gas was generated. The mixture was poured into a dilute HCl aqueous solution (240 mL), extracted with ethyl acetate (4×30 mL), washed over a saturated NH4Cl aqueous solution (50 mL), dried over anhydrous magnesium sulfate, and concentrated under vacuum to give a crude product. The crude product was further purified by distillation under reduced pressure (130° C., 4 mm Hg) to give 31.35 g (81% yield) of the desired product. 1H NMR (300 MHz, CDCl3) δ 1.47 (3H, t, J=6.4 Hz), 1.76 (1H, s), 2.38 (3H, s), 4.84 (1H, q, J=6.4 Hz), 7.20 (2H, s), 7.55 (1H, s); 3C NMR (75 MHz, CDCl3) δ 22.54, 25.16, 69.33, 124.30, 124.93, 129.34, 130.82, 136.88, 145.27; IR (neat) 3024 (s), 2997 (s), 2927 (m), 1605 (w), 1562 (w), 1494 (m), 1452 (m), 1381 (m), 1331 (w), 1255 (m), 1091 (m), 1038 (m), 1009 (m), 908 (m), 822 (m), 733 (s) cm−1; MS m/z 214 (M+), 199, 197, 171, 169, 119, 91; HRMS calcd for C9H11OBr 213.9993, found 213.9995.

1. customequipped with a magnetic stirrer bar
2. customThe flask was dried under vacuum
3. additionfilled with nitrogen
4. extractionextracted with ethyl acetate (4×30 mL)
5. washwashed over a saturated NH4Cl aqueous solution (50 mL)
6. dry with materialdried over anhydrous magnesium sulfate
7. concentrationconcentrated under vacuum
8. customto give a crude product
9. distillationThe crude product was further purified by distillation under reduced pressure (130° C., 4 mm Hg)