Lithium hydroxide, monohydrate → 3-Amino-5-phenylthiophene-2-carboxylic acid
反応式
C[O:2][C:3]([C:5]1[S:6][C:7]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=[CH:8][C:9]=1[NH2:10])=[O:4].O[Li].O>C1COCC1.CO.O>[NH2:10][C:9]1[CH:8]=[C:7]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)[S:6][C:5]=1[C:3]([OH:4])=[O:2]参加物
4
反応条件
- 温度
- 85 °C
実験手順
To a suspension of 3-Amino-5-phenyl-thiophene-2-carboxylic acid methyl ester (5 g, 21.459 mmol) in a mixture of THF:MeOH:H2O (3:2:1, 75 mL), 1N aqueous solution of LiOH.H2O (64 mL, 64.378 mmol) was added. The reaction mixture was stirred at 85° C. (external temperature) for 4 h. Solvents were removed under reduced pressure and the residue was partitioned between water and ethyl acetate. The water layer was separated and acidified with 1N HCl solution and then ethyl acetate was added to it. The organic phase was separated, dried (Na2SO4) and concentrated to obtain 3-Amino-5-phenyl-thiophene-2-carboxylic acid (4.15 g, 88%) as a yellowish solid. 1H NMR (DMSO-D6, 400 MHz): 7.59 (d, 2H), 7.40 (m, 3H), 6.92 (s, 1H).