4-溴-3,5-二乙氧基苯甲醛

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a suspension of sodium hydride (2.62 g, 60.0 mmol, 2.0 equiv; 55% free-flowing powder moistened with oil) in DMF (50 mL) under Ar was added carefully methanethiol (2.88 g, 60.0 mmol, 2.0 equiv). After 15 min, a solution of 4-bromo-3,5-diethoxy-benzaldehyde (8.2 g, 30.0 mmol, 1.0 equiv; prepared according to S. P. Dudek, H. D. Sikes, C. E. D. Chidsey J. Am Chem. Soc. 2001, 123, 8033-8038) in DMF (30 mL) was added, and the reaction mixture stirred overnight. The mixture was acidified to pH 2 by addition of a solution of 1 M HCl and extracted with ethyl acetate (3×100 mL). The combined organic phases were dried over MgSO4, the solvent removed by evaporation under reduced pressure and the crude material purified with column chromatography on silica eluting with heptane/ethyl acetate (1:1) providing 6.9 g (96%) of the title compound. 1H NMR (300 MHz, CDCl3): δ 1.50 (t, J=7.0 Hz, 6H), 2.50 (s, 3H), 4.18 (q, J=7.0 Hz, 4H), 7.02 (s, 2H), 9.88 (s, 1H). 13C NMR (75 MHz, CDCl3): δ 14.66, 17.50, 64.88, 105.71, 122.00, 135.90, 159.54, 191.31. MS (ISP): 240.9 [M+H]+. extracted with ethyl acetate (3×100 mL) The combined organic phases were dried over MgSO4 the solvent removed by evaporation under reduced pressure the crude material purified with column chromatography on silica eluting with heptane/ethyl acetate (1:1)