Reaktion #2467969

Reaktionsgleichung

ammonium chloride

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

Hydrochloric acid

→

solid

Ausbeute 81.0%

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

Ausbeute 81.0%

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto cool to rt
2. 2
   FiltrationThe solution was filtered
3. 3
   ExtraktionThe solution was extracted with ethyl acetate (4×100 mL)
4. 4
   WaschenThe combined organic layer was washed with brine
5. 5
   Trocknendried over sodium sulfate
6. 6
   FiltrationThe solution was filtered
7. 7
   Sonstigeevaporated the solvent

Vorschrift

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)+.

Quelle