反应详情

To a solution of 4-chloro-3,5-diethoxy-benzoic acid ethyl ester (5.0 g, 18.33 mmol, 1.0 equiv) in dichloromethane (25 mL) was added slowly over a time period of 15 min under slight cooling to −30° C. a solution of diisobutylaluminum hydride (55.0 mL, 55.00 mmol, 3.0 equiv; 1.0 M solution in THF). After 30 min, the excess hydride was quenched by cautious addition of methanol (10 mL) and water (2 mL). The mixture was stirred for 30 min, a solution of 1 M HCl was added and the aqueous layer extracted with ethyl acetate (3×100 mL). The combined organic phases were dried over MgSO4 and concentrated by evaporation under reduced pressure providing 4.0 g (95%) of the title compound. 1H NMR (300 MHz, CDCl3): δ 1.45 (t, J=7.0 Hz, 6H), 1.93 (br s, 1H), 4.09 (q, J=7.0 Hz, 4H), 4.62 (s, 2H), 6.57 (s, 2H). 13C NMR (75 MHz, CDCl3): δ 14.74, 64.96, 65.18, 104.30, 110.65, 140.29, 155.66. MS (ISP): 231.4 [M+H]+.

1. customthe excess hydride was quenched by cautious addition of methanol (10 mL) and water (2 mL)
2. additiona solution of 1 M HCl was added
3. extractionthe aqueous layer extracted with ethyl acetate (3×100 mL)
4. dry with materialThe combined organic phases were dried over MgSO4
5. concentrationconcentrated by evaporation under reduced pressure