Ethanol → HCID 20330114、化合物
反応式
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([O:9][CH3:10])=[CH:5][C:4]=1[CH2:11][CH2:12][CH2:13][C:14]([OH:16])=[O:15].C(=O)([O-])O.[Na+].[CH2:22](O)[CH3:23]>S(=O)(=O)(O)O>[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([O:9][CH3:10])=[CH:5][C:4]=1[CH2:11][CH2:12][CH2:13][C:14]([O:16][CH2:22][CH3:23])=[O:15]参加物
5
実験手順
To an ethanol solution (180 ml) of 4-(2,5-dimethoxyphenyl)butyric acid (52.4 g, 0.23 mole), several drops of conc. sulfuric acid are added, and the mixture is boiled for 5 hours. After cooling in the air, a saturated aqueous solution of sodium hydrogen carbonate is added for neutralization, and the mixture is concentrated under reduced pressure. The residue is diluted with ether (300 ml), washed with a saturated aqueous solution of sodium hydrogen carbonate (50 ml×2), water (50 ml×2) and a saturated aqueous solution of sodium chloride (50 ml×1) and dried over anhydrous magnesium sulfate. After filtration and evaporation, a dark red oil (55 g) is obtained, which is subjected to distillation under reduced pressure twice for purification to obtain the objective compound as a pale yellow oil (37 g, 63%). B.P. 155°-158° C. (3 mmHg). IRνmaxfilm cm-1 : 1720 (CO2Et). NMR (in CDCl3): 1.19 (3H, t, J=7.5Hz, CO2CH2CH3), 1.56-2.06 (2H, m, CH2CH2CO2Et), 2.06-2.46 (2H, m, CH2CH2CO2Et), 2.46-2.76 (2H, broad t, J=6.6Hz, CH2CH2CH2CO2Et), 3.67 (6H, s, OCH3 ×2), 4.15 (2H, q, J=7.5Hz, CO2CH2CH3), 6.15 (3H, s, aromatic proton).