Реакция #2467969

Уравнение реакции

ammonium chloride

methyl 4-methoxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate

Hydrochloric acid

→

solid

Выход 81.0%

Methyl 3-amino-4-methoxy-5-(methoxycarbonyl)thiophene-2-carboxylate

Выход 81.0%

Растворители

methanol

Условия реакции

Обработка

1. 1
   Температураto cool to rt
2. 2
   ФильтрацияThe solution was filtered
3. 3
   ЭкстракцияThe solution was extracted with ethyl acetate (4×100 mL)
4. 4
   ПромывкаThe combined organic layer was washed with brine
5. 5
   Сушкаdried over sodium sulfate
6. 6
   ФильтрацияThe solution was filtered
7. 7
   Другоеevaporated the solvent

Методика

To a solution of methyl 4-methoxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate (0.9 g, 3.27 mmol) in methanol (20 mL) was added conc. Hydrochloric acid (0.3 mL). To the above solution was added iron powder (0.91 g, 16.36 mmol) followed by an aqueous solution of ammonium chloride (0.87 g, 16.3 mmol, water: 5 mL) at rt. The reaction mixture was stirred and warmed to 70° C. for 1 h and was then allowed to cool to rt. The solution was filtered and basified with saturated sodium bicarbonate solution. The solution was extracted with ethyl acetate (4×100 mL). The combined organic layer was washed with brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent to give the product as a pale yellow color solid (0.65 g, 81%), mp 120-124° C. NMR (400 MHz, CDCl3): δ 5.39 (2H, br s), 4.01 (3H, s), 3.87 (3H, s), 3.85 (3H, s); LC-MS (positive ion mode): m/z 246 (M+H)+.

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