2-羟基-4-溴-5-甲氧基苯甲醛

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

实验步骤: To a 200 mL round-bottomed flask containing 6.90 g (25.3 mmol) 2 acetoxy-4-bromo-5-methoxybenzaldehyde (2) in 100 mL of 1% aqueous methanol at room temperature was added 5 g K2CO3, and the mixture was allowed to stir at room temperature for 1 h, at which time TLC analysis indicated complete consumption of starting material and the presence of a slightly more polar compound as the only detectable product. The reaction mixture was then neutralized to pH 5 with the addition of 1N HCl, and the solvent was subsequently removed under diminished pressure. The residue was then dissolved in ethyl acetate (200 mL), washed successively with 1N HCl (1×50 mL), saturated aqueous NaHCO3 (1×50 mL), and brine (1×50 mL), dried over Na2SO4, and concentrated under diminished pressure to give 4.97 g (85%) of the bromophenol as a brownish-red oily solid. A portion of this crude material was recrystallized from 2:1 hexanes/ethyl acetate to give white needles. 1H NMR (400 MHz, CDCl3) δ 3.89 (s, 3H, OCH3), 6.97 and 7.27 (2s, 2×1H, Ar--H), 9.83 (s, 1H, OH), 10.71 ppm (s, 1H, CHO). The remainder of the material was carried on to the next step without further purification. consumption of starting material The reaction mixture was then neutralized to pH 5 with the addition of 1N HCl the solvent was subsequently removed under diminished pressure The residue was then dissolved in ethyl acetate (200 mL) washed successively with 1N HCl (1×50 mL), saturated aqueous NaHCO3 (1×50 mL), and brine (1×50 mL) dried over Na2SO4 concentrated under diminished pressure

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

实验步骤: To a 200 mL round-bottomed flask containing 6.90 g (25.3 mmol) 2 acetoxy-4-bromo-5-methoxybenzaldehyde (2) in 100 mL of 1% aqueous methanol at room temperature was added 5 g K2CO3, and the mixture was allowed to stir at room temperature for 1 h, at which time TLC analysis indicated complete consumption of starting material and the presence of a slightly more polar compound as the only detectable product. The reaction mixture was then neutralized to pH 5 with the addition of 1N HCl, and the solvent was subsequently removed under diminished pressure. The residue was then dissolved in ethyl acetate (200 mL), washed successively with 1N HCl (1×50 mL), saturated aqueous NaHCO3 (1×50 mL), and brine (1×50 mL), dried over NA2SO4, and concentrated under diminished pressure to give 4.97 g (85%) of the bromophenol as a brownish-red oily solid. A portion of this crude material was recrystallized from 2:1 hexanes/ethyl acetate to give white needles. 1H NMR (400 MHz, CDCl3) δ3.89 (s, 3H, OCH3), 6.97 and 7.27 (2s, 2×1H, Ar--H), 9.83 (s, 1H, OH), 10.71 ppm (s, 1H, CHO). The remainder of the material was carded on to the next step without further purification. consumption of starting material The reaction mixture was then neutralized to pH 5 with the addition of 1N HCl the solvent was subsequently removed under diminished pressure The residue was then dissolved in ethyl acetate (200 mL) washed successively with 1N HCl (1×50 mL), saturated aqueous NaHCO3 (1×50 mL), and brine (1×50 mL) dried over NA2SO4 concentrated under diminished pressure