Hydrochloric Acid → HCID 86648402, compound

Temperature

-40 °C

To a solution of ((R)-2-cyano-1-ethyl-ethyl)-carbamic acid tert-butyl ester (10 mmol; 1.98 g) in Et2O (50 mL) is slowly added a 0.97 M n-hexane solution (40 mmol; 41 mL) of DIBAL under nitrogen at −78° C. The reaction mixture is warmed to −40° C. and stirred for an additional 3.5 hours. Another 1.00 M n-hexane solution (30 mmol; 30 mL) of DIBAL is added to the suspension at the same temperature. After stirring for additional 1.5 hours, the solution is quenched by careful addition of 1 ml of MeOH then immediately poured into 25 ml of saturated aqueous ammonium chloride solution in a separatory funnel. Shake mixture and leave until it reaches room temperature. Aqueous 1M HCl is added to reach a pH of 3-4. The solution is extracted three times with EtOAc and the combined organic layer is washed with an aqueous 1M HCl/brine (1:1) solution and twice with a saturated aqueous NaHCO3/brine (1:1) solution, dried over Na2SO4, filtered and concentrated under reduced pressure and purified by column chromatography on silica gel (eluent; n-hexane/EtOAc) to give ((R)-1-ethyl-3-oxo-propyl)-carbamic acid tent-butyl ester (590 mg, 29%); ESI-MS m/z: 146 [M+−tBu+2], Retention time 2.17 min (condition A).

1. stirringAfter stirring for additional 1.5 hours
2. customthe solution is quenched by careful addition of 1 ml of MeOH
3. additionthen immediately poured into 25 ml of saturated aqueous ammonium chloride solution in a separatory funnel
4. customShake mixture and leave until it
5. customreaches room temperature
6. extractionThe solution is extracted three times with EtOAc
7. washthe combined organic layer is washed with an aqueous 1M HCl/brine (1:1) solution and twice with a saturated aqueous NaHCO3/brine (1:1) solution
8. dry with materialdried over Na2SO4
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure
11. custompurified by column chromatography on silica gel (eluent; n-hexane/EtOAc)

ORD record

ord-f117289299e74971bb6428da1be57323

Source dataset

uspto-grants-2014_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08759365B2