Propanoic acid, 2-bromo-2-methyl-, ethyl ester → 2-(N-Boc-aminooxy)isobutyric acid ethyl ester

To a solution of N-Boc-hydroxylamine (5.2 g, 39.05 mmol) in ethanol (100 mL) was added potassium hydroxide (2.63 g, 46.86 mmol), the mixture stirred at room temperature until a solution was formed. 2-Bromoisobutyric acid ethyl ester (6.87 mL, 46.9 mmol) was added and the reaction mixture heated at reflux for 18 hours. The reaction mixture was cooled to room temperature then filtered, and the filtrate was concentrated in vacuo. The resultant oily residue was partitioned between water (75 mL) and diethyl ether and the aqueous fraction was extracted with diethyl ether (2×100 mL). The combined organic extracts were dried (Na2SO4), filtered and concentrated in vacuo to give the title compound as a clear oil (9.5 g, 99%). LCMS (method C): RT=2.55 min, [M+H]+=248. 1H NMR (CDCl3, 400 MHz) 4.20 (q, 2H), 1.50 (s, 6H), 1.49 (s, 9H), 1.30 (t, 3H).

1. customwas formed
2. temperaturethe reaction mixture heated
3. temperatureat reflux for 18 hours
4. temperatureThe reaction mixture was cooled to room temperature
5. filtrationthen filtered
6. concentrationthe filtrate was concentrated in vacuo
7. customThe resultant oily residue was partitioned between water (75 mL) and diethyl ether
8. extractionthe aqueous fraction was extracted with diethyl ether (2×100 mL)
9. dry with materialThe combined organic extracts were dried (Na2SO4)
10. filtrationfiltered
11. concentrationconcentrated in vacuo

ORDレコード

ord-ec5c5cb3f62f46ea91771219c60f6fd9

出典データセット

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US08841462B2