Pyridine → 4-Bromo-5-nitro-thiophene-2-carbaldehyde oxime

Participants

Reaction Steps

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.

Provenance & Evidence