反应详情

To a solution of 3-methyl-6-nitrothiopheno[2,3-d]1,2,3-triazin-4-one (1.25 g, 5.9 mmol) in methanol (50 mL) was added conc. Hydrochloric acid (0.6 mL). To the above solution was added iron powder (1.67 g, 29.5 mmol) followed by a solution of ammonium chloride (1.57 g, 29.5 mmol) in water (10 mL) at rt. The reaction mixture was stirred and warmed to 70 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 dried over sodium sulfate and filtered. Solvent was evaporated and the residue was chromatographed over silica gel column using hexane-ethyl: acetate (60:40) as eluents to give the product as a pale yellow color solid (80 mg, 7.5%), mp 190-194° C. 1H NMR (400 MHz, DMSO-d6): δ 7.40 (2H, s), 6.11 (1H, s), 3.82 (3H, s); LC-MS (negative ion mode): m/z 181 (M−H)−.

1. temperaturewarmed to 70 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