Acetone, oxime → Ethyl 2-{[(propan-2-ylidene)amino]oxy}propanoate

Temperature

0 °C

The synthesis of (±)-α-(isopropylideneaminooxy)propionic acid (2) was adapted from Melvin, S et al., Organic Syntheses, 1973, Coll. Vol. 5, 1029-37. Briefly, to a freshly prepared 1 M NaOEt solution (35 g in 1 L) was added acetone oxime (110 g, 1.505 mol) and cooled to 0° C. Ethyl α-bromopropionate (175 mL, 1.347 mol) was added at a rate that such that the temperature of the reaction mixture did not rise above 20° C. After 18 hr at rt, the mixture was filtered and the filtrate was concentrated to approximately 500 mL. Water (500 mL) was added and the mixture was extracted with 1:1 benzene:Et2O (3×150 mL). The combined extracts were washed with water (500 mL), dried over Na2SO4 and the solvent was removed and the oily residue was distilled to afford 197 g of ethyl α-(isopropylideneaminooxy)propionate as a clear oil (83%) 1H NMR (CDCl3): δ 4.5 (q, 1H, J=6.9 Hz, CH), 4.1 (m, 2H, J=7.2 Hz, O—CH2-Me), 1.84 (s, 3 H, CH3), 1.61 (s, 3 H, CH3), 1.22 (d, 3 H, J=6.9 Hz, CH—CH3), 1.17 (t, 3H, J=7.2 Hz, —CH3); B.P. 62-64° C. (4 mm).

1. customdid not rise above 20° C
2. filtrationthe mixture was filtered
3. concentrationthe filtrate was concentrated to approximately 500 mL
4. additionWater (500 mL) was added
5. extractionthe mixture was extracted with 1:1 benzene
6. washThe combined extracts were washed with water (500 mL)
7. dry with materialdried over Na2SO4
8. customthe solvent was removed
9. distillationthe oily residue was distilled

ORD record

ord-739e78a71288491680d341316f047d4c

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08779138B2