反応 #2467969

反応方程式

ammonium chloride

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

Hydrochloric acid

→

solid

収率 81.0%

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

収率 81.0%

溶媒

methanol

反応条件

後処理

1. 1
   温度to cool to rt
2. 2
   ろ過The solution was filtered
3. 3
   抽出The solution was extracted with ethyl acetate (4×100 mL)
4. 4
   洗浄The combined organic layer was washed with brine
5. 5
   乾燥dried over sodium sulfate
6. 6
   ろ過The solution was filtered
7. 7
   その他evaporated the solvent

実験手順

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)+.

出典