Реакция #2467974

Уравнение реакции

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

sodium hydroxide

HCl

→

product

Выход 38.0%

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

Выход 38.0%

Растворители

methanol

water

Условия реакции

Обработка

1. 1
   workup.ADDITIONThe mixture was diluted with ice cold water
2. 2
   Экстракцияextracted with chloroform
3. 3
   ПромывкаThe combined chloroform layer was washed with water, brine
4. 4
   Сушкаdried over sodium sulfate
5. 5
   ФильтрацияThe solution was filtered
6. 6
   Другоеevaporated the solvent
7. 7
   ДругоеThe residue was chromatographed over silica gel column

Методика

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)+.

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