Hydroxyamine hydrochloride → 2-(but-3-en-1-yloxy)-N-hydroxyethanimine

Temperature

60 °C

(But-3-en-1-yloxy)acetaldehyde (C6) (40 g from the preceding step, ≦312 mmol) was dissolved in a 2:1 mixture of ethanol and water (700 mL). Sodium acetate (128 g, 1560 mmol) was added, and the mixture was stirred for 20 minutes. Hydroxylamine hydrochloride (98%, 66.4 g, 936 mmol) was then added, and the reaction mixture was heated to 60° C. for 18 hours, at which point it was cooled to room temperature and concentrated under reduced pressure to remove ethanol. The aqueous residue was poured into water (500 mL) and extracted four times with ethyl acetate. The combined organic layers were dried over magnesium sulfate, filtered, and concentrated in vacuo. Silica gel chromatography (Gradient: 0% to 40% ethyl acetate in heptane) afforded the product as an oil, presumed from the 1H NMR spectrum to be a mixture of E and Z oximes. Yield: 24 g, 0.19 mmol, 60% over three steps. 1H NMR (400 MHz, CDCl3) δ 2.33-2.41 (m, 2H), 3.51-3.57 (m, 2H), [4.11 (d, J=5.7 Hz) and 4.36 (d, J=3.7 Hz), total 2H], 5.04-5.16 (m, 2H), 5.76-5.89 (m, 1H), [6.92 (t, J=3.7 Hz) and 7.51 (t, J=5.6 Hz), total 1H].

1. temperaturewas cooled to room temperature
2. concentrationconcentrated under reduced pressure
3. customto remove ethanol
4. additionThe aqueous residue was poured into water (500 mL)
5. extractionextracted four times with ethyl acetate
6. dry with materialThe combined organic layers were dried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated in vacuo

ORD record

ord-747d3018352945bf9fd3586344acb099

Source dataset

uspto-grants-2015_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08933221B2