Reacción #2467973

Ecuación de reacción

water

ammonium hydroxide

methyl 3-[(dimethylamino)diazenyl]-5-phenylthiophene-2-carboxylate

→

solid

Rendimiento 8.0%

3-[(Dimethylamino)diazenyl]-5-phenylthiophene-2-carboxamide

Rendimiento 8.0%

Disolventes

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONThe solution was poured into ice
2. 2
   Extracciónextracted with chloroform
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
8. 8
   Otroto give the product
9. 9
   OtroThe crude product was recrystallized from chloroform-hexane

Procedimiento

To an ice cold (0-5° C.) solution of ammonium hydroxide (80 mL) was added a solution of methyl 3-[(dimethylamino)diazenyl]-5-phenylthiophene-2-carboxylate (2.2 g) in THF (15 mL) for 5 min followed by catalytic amount of PEG-400 and the mixture was stirred at rt for 36 h. The solution was poured into ice cooled water and extracted with chloroform. 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 (94:6) as eluents to give the product. The crude product was recrystallized from chloroform-hexane to give the product as a yellow color solid (170 mg, 8%), mp 220-222° C. IR (neat) νmax, 3343, 2922, 2855, 1642, 1595, 1221, 1023, 880, 841 cm−1; 1H NMR (400 MHz, CDCl3): δ 8.30 (1H, br s), 7.64-7.66 (2H, m), 7.53 (1H, s), 7.30-7.41 (3H, m), 6.34 (1H, br s), 3.59 (3H, s), 3.20 (3H, s); 13C NMR (100 MHz, CDCl3): δ 164.7, 151.1, 146.7, 133.9, 128.9, 128.5, 125.8, 125.4, 114.7, 43.6, 36.5; LC-MS (positive ion mode): m/z 297 (M+Na)+.

Fuente