Diisobutylaluminum hydride → tert-Butyl (3-oxo-2-phenylpropyl)carbamate

Temperature

-78 °C

A solution of methyl 3-[(tert-butoxycarbonyl)amino]-2-phenylpropanoate from Step A (2.1 g, 7.52 mmol) in anhydrous dichloromethane (75 mL) was cooled to −78° C. under nitrogen and DIBAL-H (15 mL, 15 mmol, 1.0 M in hexanes) was added to the solution dropwise over 45 minutes. This solution was then stirred at −78° C. for 1 h. The reaction was then quenched by the addition of a saturated aqueous solution of Rochel's salt (75 mL) and the biphasic solution was stirred at ambient temperature for 30 minutes. The layers were separated and the aqueous layer was extracted twice with DCM. The combined organics were dried over sodium sulfate, filtered, and concentrated in vacuo to provide a residue. The residue was applied to a silica gel column for purification, eluting with a gradient of 1-3% methanol in DCM to yield the title compound. MS: m/z=250 (M+1).

1. customThe reaction was then quenched by the addition of a saturated aqueous solution of Rochel's salt (75 mL)
2. stirringthe biphasic solution was stirred at ambient temperature for 30 minutes
3. customThe layers were separated
4. extractionthe aqueous layer was extracted twice with DCM
5. dry with materialThe combined organics were dried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customto provide a residue
9. customThe residue was applied to a silica gel column for purification
10. washeluting with a gradient of 1-3% methanol in DCM

ORD record

ord-bfb1f0ea9a99494f9ccf9aa641bf960f

Source dataset

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08507477B2