Sulfuric Acid → Ethyl [(6S)-6-(3,5-difluorophenyl)-3,3-dimethyl-2,4-dioxopiperidin-1-yl]acetate

HRID 1866658Notes

Reaction equation

[F:1][C:2]1[CH:3]=[C:4]([C@H:9]2[N:14]([CH2:15][C:16]([O:18][CH2:19][CH3:20])=[O:17])[C:13](=[O:21])[C:12]([CH3:23])([CH3:22])[C@@H:11]([OH:24])[CH2:10]2)[CH:5]=[C:6]([F:8])[CH:7]=1.OS(O)(=O)=O>CC(C)=O.O.[O-2].[O-2].[O-2].[Cr+6]>[F:1][C:2]1[CH:3]=[C:4]([C@H:9]2[N:14]([CH2:15][C:16]([O:18][CH2:19][CH3:20])=[O:17])[C:13](=[O:21])[C:12]([CH3:23])([CH3:22])[C:11](=[O:24])[CH2:10]2)[CH:5]=[C:6]([F:8])[CH:7]=1

Participants

Conditions

Temperature: 0 °C

Procedure

To a solution of ethyl [(4S,6S)-6-(3,5-difluorophenyl)-4-hydroxy-3,3-dimethyl-2-oxopiperidin-1-yl]acetate (470 mg, 1.377 mmol, described in Intermediate 21) in acetone (24 mL) at 0° C. was added a solution of chromium (VI) trioxide (174 mg, 1.740 mmol) in H2O (0.5 mL) and H2SO4 (0.147 mL, 2.75 mmol), in three portions over 5 min and the mixture was stirred at 0° C. for 30 min. Most of the acetone was removed by concentration in vacuo, and the residue was basified with saturated aqueous NaHCO3 (75 mL) and extracted with EtOAc (2×100 mL). The combined organic layers were washed with brine (40 mL) and dried over Na2SO4, filtered, and concentrated in vacuo. The crude product was purified by silica gel chromatography, eluting with a gradient of CH2Cl2:CH3OH—100:0 to 92:8, to give the title compound. MS: m/z=340 (M+1).

Workup

customMost of the acetone was removed by concentration in vacuo
extractionextracted with EtOAc (2×100 mL)
washThe combined organic layers were washed with brine (40 mL)
dry with materialdried over Na2SO4
filtrationfiltered
concentrationconcentrated in vacuo
customThe crude product was purified by silica gel chromatography
washeluting with a gradient of CH2Cl2

Sources & evidence

ORD record: ord-69a7cdb2f6b54d1b9c9972eb3e664c66
Source dataset: uspto-grants-2009_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07629338B2

Reaction notes

Loading…