反应详情

An ice-cold mixture of 2,5-dichloro-thiophene-3-carboxylic acid methylamide (475 mg) in H2SO4 (20 mL, 95-98%) was treated with fuming HNO3 (25 mL). The mixture was stirred for 1 hour and slowly poured onto ice, extracted with ethyl acetate three times, and dried over sodium sulfate. Filtration and concentration provided 2,5-dichloro-4-nitro-thiophene-3-carboxylic acid methylamide (565 mg): 1H NMR (300 MHz, CDCl3) δ 6.0 (bs, 1H), 3.0 (d, 3H).

1. additionslowly poured onto ice
2. extractionextracted with ethyl acetate three times
3. dry with materialdried over sodium sulfate
4. filtrationFiltration and concentration