反应详情

Hydroxylamine hydrochloride (85 g, 1.2 mol) was added to a solution of 4-bromo-5-nitro-thiophene-2-carbaldehyde (234 mg, 0.529 mmol, Example 286: step a) in EtOH (7.5 mL, 200 proof—anhydrous):pyridine (100 mL, anhydrous) at rt over 5 min. The reaction mixture was heated to reflux overnight, then cooled to rt. The solvents were removed in vacuo resulting in a solid residue that was washed with water and filtered. The solid was dried overnight under high vacuum to afford the title compound as a yellow solid (225 g, 88%). The solid was used for the next step without further characterization.

1. temperatureThe reaction mixture was heated
2. temperatureto reflux overnight
3. customThe solvents were removed in vacuo
4. customresulting in a solid residue that
5. washwas washed with water
6. filtrationfiltered
7. customThe solid was dried overnight under high vacuum