Ethyl Acetate → (3aS,7aS)-octahydro-1,3-benzoxazol-2-one

The (1S,2S)-2-Aminocyclohexanole (750 mg, 6.51 mmol) and the 2-Nitrophenyl chloroformate (1378 mg, 6.84 mmol) were stirred in DCE (15 mL) with DIEA (2.39 mL, 13.68 mmol) in a sealed vial at 90° C. for 1 h. The reaction mixture was given into a separating funnel with 50 mL EtOAc and 50 mL saturated NaHCO3 solution. The aqueous layer was washed with 50 mL EtOAc. The organic layers were combined and washed with 50 mL H2O, 50 mL brine, dried with Na2SO4, filtered and concentrated. The residue was purified by flash chromatography (hexane/EtOAc: 7:3→3:7) to give the title compound (770 mg, 5.13 mmol). tR: 0.69 min (LC-MS 1); 1H NMR (400 MHz, <dmso>) δ ppm 1.19-1.44 (m, 3H) 1.45-1.61 (m, 1H) 1.65 (d, J=9.77 Hz, 1H) 1.76 (d, J=11.34 Hz, 1H) 1.82-1.93 (m, 1H) 1.93-2.10 (m, 1H) 3.03-3.23 (m, 1H) 3.74 (td, J=11.34, 3.52 Hz, 1H) 7.53 (br. s., 1H)

1. washThe aqueous layer was washed with 50 mL EtOAc
2. washwashed with 50 mL H2O, 50 mL brine
3. dry with materialdried with Na2SO4
4. filtrationfiltered
5. concentrationconcentrated
6. customThe residue was purified by flash chromatography (hexane/EtOAc: 7:3→3:7)

ORD record

ord-316e1074022f443ab28467a8b23420f5

Source dataset

uspto-grants-2014_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08865894B2