6-Bromoquinoxaline → 1-(Quinoxalin-6-yl)ethan-1-one

HRID 1271385Notes

Reaction equation

HRID 1271385 reaction equation
Br[C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[N:8]=[CH:7][CH:6]=[N:5]2.[CH2:12]([O:14]C([Sn](CCCC)(CCCC)CCCC)=C)[CH3:13].F[B-](F)(F)F.C([PH+](C(C)(C)C)C(C)(C)C)(C)(C)C>CN(C=O)C.C([O-])(=O)C.[Pd+2].C([O-])(=O)C>[N:8]1[C:9]2[C:4](=[CH:3][C:2]([C:12](=[O:14])[CH3:13])=[CH:11][CH:10]=2)[N:5]=[CH:6][CH:7]=1

Participants

6

Reactant 3

HCID 6109396-BromoquinoxalineHCID 619414Stannane, tributyl(1-ethoxyethenyl)-HCID 2734635Tri-tert-butylphosphine tetrafluoroborate

Product 1

HCID 226312491-(Quinoxalin-6-yl)ethan-1-oneYield 51.1%

Reagents, catalysts & solvents 2

HCID 167845palladium(II) acetateCatalystHCID 6228DimethylformamideSolvent

Procedure

A solution of 6-bromo-quinoxaline (261 mg, 1.25 mmol), 1-ethoxyvinyltri-n-butyltin (0.47 mL, 1.4 mmol), palladium(II) acetate (16 mg) and tri-t-butylphosphonium tetrafluoroborate (41 mg) in anhydrous DMF (4 mL) under a nitrogen atmosphere was heated at 120° C. for 1 hr. The reaction mixture was cooled to ambient temperature and partitioned between ethyl acetate (25 mL) and H2O (10 mL). The organic extraction was washed with brine, dried (MgSO4), filtered, and concentrated. The concentrate was chromatographed on silica gel eluting with ethyl acetate:hexanes (1:1) to provide 110 mg of the title compound. 1H NMR (300 MHz, CDCl3) δ 2.79 (s, 3 H), 8.18 (d, J=9 Hz, 1 H), 8.36 (dd, J=9 Hz, J=3 Hz, 1 H), 8.70 (d, J=3 Hz, 1 H), 8.95 (s, 2 H); MS (DCl/NH3) m/z 173 (M+H)+.

Workup

  1. custompartitioned between ethyl acetate (25 mL) and H2O (10 mL)
  2. extractionThe organic extraction
  3. washwas washed with brine
  4. dry with materialdried (MgSO4)
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customThe concentrate was chromatographed on silica gel eluting with ethyl acetate:hexanes (1:1)

Sources & evidence

ORD record
ord-bf69d84871384c1eb6111f8fa0db674c
Source dataset
uspto-grants-2007_04
Patent number
US07205316B2

Reaction notes

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