4-Methylmorpholine → Boc-O-benzyl-L-serine N,O-dimethylhydroxamide

To a solution of O-benzyl-N-(tert-butoxycarbonyl)serine (5.9 g, 20.0 mmol) in CH2Cl2 (20 mL) was added N,O-dimethylhydroxylamine hydrochloride (1.95 g, 20.0 mmol) followed by N-methylmorpholine (2.20 mL, 19.98 mmol). The mixture was cooled to 0° C. and treated with a 1 M solution of N,N-dicyclohexylcarbodiimide in CH2Cl2 (20.0 mL, 20.0 mmol). The mixture was allowed to warm to ambient temperature while stirring under inert atmosphere for 18 h. The mixture was filtered, washing the solid residue with excess CH2Cl2, and the filtrate was concentrated in vacuo. The resulting oil was suspended in EtOAc, stirred for 20 min, and filtered once more, washing with EtOAc. The filtrate was concentrated to an orange oil which was purified by silica gel chromatography (20% to 60% EtOAc/hexanes) to afford the title compound as a colorless oil. 1H NMR (500 MHz, CDCl3) δ 7.35-7.25 (m, 5H), 5.44 (d, J=8.4 Hz, 1H), 4.88 (d, J=3.2 Hz, 1H), 4.53 (dd, J=12.4, 28.8 Hz, 2H), 3.71 (s, 3H), 3.69-3.64 (m, 2H), 3.21 (s, 3H), 1.44 (s, 9H). ES MS (M+1−100, for loss of BOC group)=239.2.

1. temperatureto warm to ambient temperature
2. filtrationThe mixture was filtered
3. washwashing the solid residue with excess CH2Cl2
4. concentrationthe filtrate was concentrated in vacuo
5. stirringstirred for 20 min
6. filtrationfiltered once more
7. washwashing with EtOAc
8. concentrationThe filtrate was concentrated to an orange oil which
9. customwas purified by silica gel chromatography (20% to 60% EtOAc/hexanes)

ORD 기록

ord-505c3537c9db47c99382f0981cf0130a

출처 데이터셋

uspto-grants-2010_10

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US07820680B2