Reacción #2467995

Ecuación de reacción

3-amino-5-phenylthiophene-2-carboxamide

sodium nitrite

→

solid

Rendimiento 51.3%

6-Phenyl-3H-thiopheno[3,2-d]1,2,3-triazin-4-one

Rendimiento 51.3%

Disolventes

sulfuric acid

sulfuric acid

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONwhile adding
2. 2
   Otroshould keep between −5-0° C.
3. 3
   workup.ADDITIONAfter addition
4. 4
   TemperaturaThe reaction mixture was cooled
5. 5
   workup.ADDITIONpoured
6. 6
   Otrointo crushed ice slowly
7. 7
   workup.STIRRINGwith stirring for 15 min
8. 8
   workup.STIRRINGstirred at the same temperature for 15 min
9. 9
   ExtracciónThe solution was extracted with ethyl acetate (3×50 mL)
10. 10
    Lavadothe combined EtOAc layer was washed with water, brine
11. 11
    Secadodried over sodium sulfate
12. 12
    FiltraciónThe solution was filtered
13. 13
    Otroevaporated the solvent

Procedimiento

To an ice cold solution (0° C.) of 3-amino-5-phenylthiophene-2-carboxamide (0.37 g, 1.7 mmol) in concentrated sulfuric acid (20 mL) was added a cold (0° C.) solution of sodium nitrite (120 mg, 1.86 mmol) in concentrated sulfuric acid (8 mL) for 10 min (while adding, the temperature should keep between −5-0° C.). After addition, the mixture was stirred at 0° C. for 1 h and at rt for 1 h. The reaction mixture was cooled and poured into crushed ice slowly with stirring for 15 min and stirred at the same temperature for 15 min. The solution was extracted with ethyl acetate (3×50 mL) and the combined EtOAc layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent to give the product as an off-white color solid (200 mg, 39%), my 178-180° C. 1H NMR (400 MHz, CDCl3): δ 12.30 (1H, br s), 7.86 (1H, s), 7.73-7.75 (2H, m), 7.49-7.54 (3H, m); LC-MS (negative ion mode): m/z 228 (M−H)−.

Fuente