Reacción #2467969

Ecuación de reacción

ammonium chloride

methyl 4-methoxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate

Hydrochloric acid

→

solid

Rendimiento 81.0%

Methyl 3-amino-4-methoxy-5-(methoxycarbonyl)thiophene-2-carboxylate

Rendimiento 81.0%

Disolventes

methanol

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturato cool to rt
2. 2
   FiltraciónThe solution was filtered
3. 3
   ExtracciónThe solution was extracted with ethyl acetate (4×100 mL)
4. 4
   LavadoThe combined organic layer was washed with brine
5. 5
   Secadodried over sodium sulfate
6. 6
   FiltraciónThe solution was filtered
7. 7
   Otroevaporated the solvent

Procedimiento

To a solution of methyl 4-methoxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate (0.9 g, 3.27 mmol) in methanol (20 mL) was added conc. Hydrochloric acid (0.3 mL). To the above solution was added iron powder (0.91 g, 16.36 mmol) followed by an aqueous solution of ammonium chloride (0.87 g, 16.3 mmol, water: 5 mL) at rt. The reaction mixture was stirred and warmed to 70° C. for 1 h and was then allowed to cool to rt. The solution was filtered and basified with saturated sodium bicarbonate solution. The solution was extracted with ethyl acetate (4×100 mL). The combined organic layer was washed with brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent to give the product as a pale yellow color solid (0.65 g, 81%), mp 120-124° C. NMR (400 MHz, CDCl3): δ 5.39 (2H, br s), 4.01 (3H, s), 3.87 (3H, s), 3.85 (3H, s); LC-MS (positive ion mode): m/z 246 (M+H)+.

Fuente