Boron Trichloride → (3R)-1-Benzyl-3-Ethyl-7-fluoro-4-(4-hydroxybenzoyl)-3,4-dihydroquinoxalin-2(1H)-one

HRID 898216Notes

Reaction equation

HRID 898216 reaction equation
[CH2:1]([N:8]1[C:17]2[C:12](=[CH:13][CH:14]=[C:15]([F:18])[CH:16]=2)[N:11]([C:19](=[O:28])[C:20]2[CH:25]=[CH:24][C:23]([O:26]C)=[CH:22][CH:21]=2)[C@H:10]([CH2:29][CH3:30])[C:9]1=[O:31])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.B(Cl)(Cl)Cl>[I-].C([N+](CCCC)(CCCC)CCCC)CCC.C(Cl)Cl>[CH2:1]([N:8]1[C:17]2[C:12](=[CH:13][CH:14]=[C:15]([F:18])[CH:16]=2)[N:11]([C:19](=[O:28])[C:20]2[CH:21]=[CH:22][C:23]([OH:26])=[CH:24][CH:25]=2)[C@H:10]([CH2:29][CH3:30])[C:9]1=[O:31])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 2

HCID 25135Boron TrichlorideHCID 69223935(3R)-1-benzyl-3-ethyl-7-fluoro-4-(4-methoxybenzoyl)-3,4-dihydroquinoxalin-2(1H)-one

Product 1

HCID 11682854(3R)-1-Benzyl-3-Ethyl-7-fluoro-4-(4-hydroxybenzoyl)-3,4-dihydroquinoxalin-2(1H)-oneYield 156.8%

Reagents, catalysts & solvents 2

HCID 67553Tetrabutylammonium IodideCatalystHCID 6344DichloromethaneSolvent2×

Conditions

Temperature
0 °C

Procedure

To a stirred solution of (3R)-1-benzyl-3-ethyl-7-fluoro-4-(4-methoxybenzoyl)-3,4-dihydroquinoxalin-2(1H)-one (0.17 g, 0.41 mmol) and tetrabutylammonium iodide (0.28 g, 0.76 mmol) in methylene chloride (4 mL) at −78° C. was added a 1 M solution of boron trichloride in methylene chloride (2.8 mL, 2.8 mmol). Stirring was continued at −78° C. for 5 minutes, and the reaction was warmed to 0° C., where it was stirred for 10 h. Ice water was then added and stirred thoroughly. The layers were separated. The organic layer was washed with water and brine and dried over magnesium sulfate. Evaporation of the solvent under reduced pressure gave an oil (0.26 g). The product was purified via Biotage Horizon® (SiO2, gradient from 5% EtOAc/hexane to 35% EtOAc/hexane) to quantitatively yield (3R)-1-benzyl-3-ethyl-7-fluoro-4-(4-hydroxybenzoyl)-3,4-dihydroquinoxalin-2(1H)-one as a colorless oil. [α]D25=250° (c=0.0097 G/ML, CHCl3); MS (ESI) m/z 405 ([M+H]+); MS (ESI) m/z 403 ([M−H]−); HRMS: calcd for C24H21FN2O3 0.67H2O, 416.2207; found (ESI+), 405.16006.

Workup

  1. stirringwhere it was stirred for 10 h
  2. stirringstirred thoroughly
  3. customThe layers were separated
  4. washThe organic layer was washed with water and brine
  5. dry with materialdried over magnesium sulfate
  6. customEvaporation of the solvent under reduced pressure

Sources & evidence

ORD record
ord-fde716a8a0e340b982cfbbf23fa63d5a
Source dataset
uspto-grants-2008_04
Patent number
US07351709B2

Reaction notes

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