Methanol → 4-Chloro-benzaldehyde oxime

To a suspension of 4-chlorobenzaldehyde (70 g, 0.50 mol) and hydroxylamine hydrochloride (38.06 g, 0.55 mol) in a mixture of water (125 ml), methanol (150 ml) and ice (215 ml) was added an aqueous solution of sodium hydroxide (43.82 g NaOH in 100 ml water). Ice was occasionally added to keep the temperature below room temperature. The resulting almost clear solution was stirred for two hours before it was extracted with methyl t-butyl ether (500 ml). The remaining aqueous layer was acidified with 6 N HCl (95 ml) to pH around 5. The suspension was extracted with dichloromethane (500 ml). The organic phase was dried and concentrated to give the title compound as a white solid (63.39 g): NMR (CDCl3, 200 MHz): δ=8.09 (s, 1H), 7.66 (br s, 1H), 7.49 (m, 2H), 7.34 (m, 2H).

1. additionIce was occasionally added
2. customthe temperature below room temperature
3. extractionwas extracted with methyl t-butyl ether (500 ml)
4. extractionThe suspension was extracted with dichloromethane (500 ml)
5. customThe organic phase was dried
6. concentrationconcentrated

ORD record

ord-1cfc3514b5814887b6e26fb4e01d1f51

Source dataset

uspto-grants-2012_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08269008B2