Réaction #2467967

Équation de réaction

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

sulfuric acid

nitric acid

→

semi-solid

Rendement 20.0%

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

Rendement 20.0%

Solvants

water

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONThe mixture was poured into ice
2. 2
   Extractionextracted with ethyl acetate (3×100 mL)
3. 3
   LavageThe combined organic layer was washed with water, brine
4. 4
   Séchagedried over sodium sulfate
5. 5
   FiltrationThe solution was filtered
6. 6
   Autreevaporated the solvent
7. 7
   AutreThe residue was chromatographed over silica gel column

Mode opératoire

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%).

Source