Реакция #2467967

Уравнение реакции

Methyl 4-hydroxy-5-(methoxycarbonyl)thiophene-2-carboxylate

sulfuric acid

nitric acid

→

semi-solid

Выход 20.0%

Methyl 4-hydroxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate

Выход 20.0%

Растворители

water

Условия реакции

Обработка

1. 1
   workup.ADDITIONThe mixture was poured into ice
2. 2
   Экстракцияextracted with ethyl acetate (3×100 mL)
3. 3
   ПромывкаThe combined organic 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

Methyl 4-hydroxy-5-(methoxycarbonyl)thiophene-2-carboxylate (5 g, 23.14 mmol) was added slowly for 15 min at 0 to −5° C. to concentrated sulfuric acid (25 mL). Then concentrated nitric acid (3.2 mL, 70%, 34.7 mmol) was added to the above reaction mixture for 10 min and stirred at the same temperature for 1 h. The mixture was poured into ice cooled water and extracted with ethyl acetate (3×100 mL). The combined organic 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 chloroform-methanol (95:5) as eluents to give the product as a yellow color semi-solid (1.2 g, 20%).

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