反応 #2467974

反応方程式

methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate

sodium hydroxide

HCl

→

product

収率 38.0%

3-[(dimethylamino)diazenyl]thiophene-2-carboxylic acid

収率 38.0%

溶媒

methanol

water

反応条件

後処理

1. 1
   workup.ADDITIONThe mixture was diluted with ice cold water
2. 2
   抽出extracted with chloroform
3. 3
   洗浄The combined chloroform layer was washed with water, brine
4. 4
   乾燥dried over sodium sulfate
5. 5
   ろ過The solution was filtered
6. 6
   その他evaporated the solvent
7. 7
   その他The residue was chromatographed over silica gel column

実験手順

To a solution of methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate (200 mg, 0.93 mmol) in methanol (10 mL) was added a solution of sodium hydroxide (93 mg, 2.3 mmol) in water (2 mL) and stirred at rt for 2 h. The mixture was diluted with ice cold water and acidified with dil. HCl and extracted with chloroform. The combined chloroform layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-ethyl acetate (80:20) as eluents to give the product as an off-white solid (70 mg, 38%), mp 108-110° C. IR (neat) νmax 3402, 3082, 2923, 1708, 1218, 1116, 1066, 1016, 880, 773 cm−1; 1H NMR (400 MHz, CDCl3): δ 12.21 (1H, s), 7.47 (1H, d, J=5.2 Hz), 7.30 (1H, d, J=5.2 Hz), 3.65 (3H, s), 3.28 (3H, s); LC-MS (positive ion mode): m/z 200 (M+H)+.

出典