反应详情

To a solution of methyl 5-methyl-4-nitroselenophene-2-carboxylate (2.3 g, 9.28 mmol) in a mixture of water (5 mL) and methanol (40 mL) was added conc. hydrochloric acid (1.0 mL). To the above solution was added iron powder (2.6 g, 46.4 mmol) followed by ammonium chloride (2.5 g, 46.4 mmol) at rt. The reaction mixture was refluxed 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) and the combined organic layer was dried over sodium sulfate and filtered. Solvent was evaporated and the residue was chromatographed over silica gel column using hexane-ethyl acetate (80:20) as eluent to give methyl 4-amino-5-methylselenophene-2-carboxylate (1.6 g, 79%), mp 66-68° C. 1H NMR (400 MHz, DMSO-d6): δ 7.57 (1H, s, H-3), 4.72 (2H, br s, —NH2), 3.73 (3H, s, —COOCH3), 2.24 (3H, s, —CH3).

1. temperatureThe reaction mixture was refluxed for 1 h
2. filtrationThe solution was filtered
3. extractionThe solution was extracted with ethyl acetate (4×100 mL)
4. dry with materialthe combined organic layer was dried over sodium sulfate
5. filtrationfiltered
6. customSolvent was evaporated
7. customthe residue was chromatographed over silica gel column