反应详情

A mixture of 4-bromo-5-nitro-thiophene-2-carbaldehyde oxime (216 g, 0.86 mol, Example 286: step b) and acetic anhydride (1 L, 10.6 mol) was heated to reflux for 4 hrs. The reaction mixture was cooled to rt and the solvents were removed in vacuo. The crude reaction mixture was diluted in methylene chloride and washed with water. The organic layer was dried over magnesium sulfate and concentrated in vacuo resulting in a residue, which was stirred in diethyl ether/hexanes and filtered to afford the title compound as a yellow solid (170.2 g, 85%). 1H-NMR (DMSO-d6): δ 8.25 (s, 1H).

1. temperaturewas heated
2. temperatureto reflux for 4 hrs
3. customthe solvents were removed in vacuo
4. customThe crude reaction mixture
5. washwashed with water
6. dry with materialThe organic layer was dried over magnesium sulfate
7. concentrationconcentrated in vacuo
8. customresulting in a residue, which
9. filtrationfiltered