反应详情

Hydroxylamine hydrochloride (420 mg, 6.1 mmol) and pyridine (0.5 mL) were added to a solution of methyl 5-formylthiophene-2-carboxylate (690 mg, 4.1 mmol) in EtOH (25 mL). The reaction mixture was refluxed for 3 h, cooled to room temperature and concentrated under reduced pressure. The residue was dissolved in diethyl ether, the organic layer was washed with water and brine, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure to get product methyl 5-((hydroxyimino)methyl)thiophene-2-carboxylate (440 mg, yield 60%), which was carried through without any further purification. 1H NMR (400 MHz, DMSO-d6) δ 12.5 (s, 1H), 7.98 (s, 1H), 7.78 (d, J=4.1 Hz, 1H), 7.51 (d, J=4.1 Hz, 1H), 3.82 (s, 3H). MS (ESI) m/z: Calculated for C7H7NO3S: 185.01. found: 186.0 (M+H)+.

1. temperatureThe reaction mixture was refluxed for 3 h
2. concentrationconcentrated under reduced pressure
3. dissolutionThe residue was dissolved in diethyl ether
4. washthe organic layer was washed with water and brine
5. dry with materialdried over anhydrous sodium sulfate
6. customThe solvent was removed under reduced pressure