反应详情

温度

2.5 °C

To a solution of methyl 4-amino-5-methylselenophene-2-carboxylate (1.2 g, 5.5 mmol) and conc. HCl (2.2 mL, 0.803 g, 22 mmol) in water (12.5 mL) was added sodium nitrite (0.42 g, 6.05 mmol) in portions for 5 min at 0° C. After stirring at 0-5° C. for 0.5 h, the reaction mixture was added to the solution of potassium carbonate (2.9 g, 20.9 mmol) and dimethylamine (2.23 mL, 40%, 19.8 mmol) in water (15.6 mL) at 0° C. The mixture was stirred at 0-10° C. for 1 h and poured into ice cooled water. The solution was extracted with chloroform (3×100 mL) and the combined chloroform 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 hexane-EtOAc (95:5) as eluents to give the product as a green color solid (550 mg, 36%), mp 80-82° C. IR (neat) νmax 2949, 1708, 1242, 1175, 1150, 1071, 1054, 920, 876 cm−1; 1H NMR (400 MHz, CDCl3): δ 8.21 (1H, s, H-3), 3.84 (3H, s, —COOCH3), 3.27 (6H, br s, —N(CH3)2), 2.62 (3H, s, Ar—CH3); LC-MS (positive ion mode): m/z 276 (M+H)+.

1. stirringThe mixture was stirred at 0-10° C. for 1 h
2. additionpoured into ice
3. extractionThe solution was extracted with chloroform (3×100 mL)
4. washthe combined chloroform layer was washed with water, brine
5. dry with materialdried over sodium sulfate
6. filtrationThe solution was filtered
7. customevaporated the solvent
8. customThe residue was chromatographed over silica gel column