Reacción #2467967

Ecuación de reacción

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

sulfuric acid

nitric acid

→

semi-solid

Rendimiento 20.0%

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

Rendimiento 20.0%

Disolventes

water

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONThe mixture was poured into ice
2. 2
   Extracciónextracted with ethyl acetate (3×100 mL)
3. 3
   LavadoThe combined organic layer was washed with water, brine
4. 4
   Secadodried over sodium sulfate
5. 5
   FiltraciónThe solution was filtered
6. 6
   Otroevaporated the solvent
7. 7
   OtroThe residue was chromatographed over silica gel column

Procedimiento

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%).

Fuente