31127-39-6

29668-44-8

31127-39-6

GENERAL PROCEDURE: 1,4-Benzodioxane-6-carbaldehyde (30-35 mmol) was used as a raw material, which was suspended in ethanol (50 mL), and hydroxylamine hydrochloride (NH2OH-HCl, 2 eq.) and sodium hydroxide granules (NaOH, 1.8 eq.) were added sequentially. The reaction mixture was stirred at 80 °C for 4 h. After completion of the reaction, the solvent was removed by vacuum concentration. The crude product was extracted with ethyl acetate (EtOAc, 200 mL) and the organic layer was washed sequentially with 1N hydrochloric acid (2 x 200 mL) and water (4 x 200 mL), after which it was dried with anhydrous magnesium sulfate (MgSO4) and concentrated in vacuum. If thin layer chromatography (TLC) detection showed the presence of impurities, the solid was washed with a minimal amount of cold ether (Et2O) to finally obtain 2,3-dihydrobenzo[b][1,4]dioxane-6-carbaldehyde oxime as a white powder.