Reacción #2467965

Ecuación de reacción

ammonium hydroxide

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

sulfuric acid

nitric acid

→

solid

Rendimiento 26.0%

Methyl 3-[(dimethylamino)diazenyl]-5-nitrothiophene-2-carboxylate

Rendimiento 26.0%

Disolventes

water

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONThe mixture was poured into ice
2. 2
   ExtracciónThe solution was extracted with chloroform (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 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate (2 g, 9.38 mmol) was added slowly for 15 min at 0 to −5° C. to concentrated sulfuric acid (20 mL). Then concentrated nitric acid (0.54 mL, 70%, 10.7 mmol) was added to the above reaction mixture for 10 min and stirred at the same temperature for 1 h and rt for 16 h. The mixture was poured into ice cooled water and basified with ammonium hydroxide. The solution was extracted with chloroform (3×100 mL) and 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 hexane-ethyl acetate (80:20) as eluents to give the product as a yellow color solid (450 mg, 26%), mp 128-130° C.

Fuente