Dicyclohexylcarbodiimide → Tert-butyl (1-(methoxy(methyl)amino)-2-methyl-1-oxopropan-2-YL)carbamate

To a stirred mixture of Boc-Aib-OH (5 g, 24.61 mmol, 1 eq), MeNHOMe.HCl (2.88 g, 29.53 mmol, 1.2 eq), DMAP (3.61 g, 29.53 mmol, 1.2 eq), i-Pr2NEt (5.02 mL, 29.53 mmol, 1.2 eq) and CH2Cl2 (100 mL) was added DCC (6.09 g, 29.53 mmol, 1.2 eq). The mixture was stirred at room temperature for 5 days. The mixture was filtered to remove precipitated N,N′-dicyclohexylurea and the filtrate was evaporated under reduced pressure. The residue was dissolved in ethyl acetate (200 mL), washed with 10% aqueous citric acid (3×200 mL), 10% aqueous NaHCO3 (3×200 mL) and saturated aqueous sodium chloride (3×200 mL), and dried over MgSO4. Removal of the solvent yielded the crude product which was purified by column chromatography (hexane/ethyl acetate 60:40) to afford [1-(methoxy-methyl-carbamoyl)-1-methyl-ethyl]-carbamic acid tert-butyl ester (4.85 g, 80%) as a white solid. 1H NMR (200 MHz, CDCl3) δ (ppm): 1.43 (s, 6H), 1.58 (s, 9H), 3.22 (s, 3H), 3.69 (s, 3H), 6.95 (bs, 1H). MS (ESI, +ve ion): m/z 247.2 (M+1)+.

1. filtrationThe mixture was filtered
2. customto remove
3. customprecipitated N,N′-dicyclohexylurea
4. customthe filtrate was evaporated under reduced pressure
5. dissolutionThe residue was dissolved in ethyl acetate (200 mL)
6. washwashed with 10% aqueous citric acid (3×200 mL), 10% aqueous NaHCO3 (3×200 mL) and saturated aqueous sodium chloride (3×200 mL)
7. dry with materialdried over MgSO4
8. customRemoval of the solvent
9. customyielded the crude product which
10. customwas purified by column chromatography (hexane/ethyl acetate 60:40)

ORD 기록

ord-b0473bb2be6a4856908cc5f911d70216

출처 데이터셋

uspto-grants-2012_03

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US08129355B2