Lithium Chloride → 6-Ethenylquinoxaline

HRID 642874Notes

Reaction equation

HRID 642874 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.[Cl-].[Li+].[CH2:14](C([Sn])=C(CCCC)CCCC)[CH2:15]CC>C1(C)C=CC=CC=1.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH:14]([C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[N:8]=[CH:7][CH:6]=[N:5]2)=[CH2:15]

Participants

6

Reactant 3

HCID 433294Lithium ChlorideHCID 6109396-BromoquinoxalineHCID 53438229Tri(butyl)vinyltin

Product 1

HCID 451216126-EthenylquinoxalineYield 87%

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 1140TolueneSolvent

Procedure

A mixture of 6-Bromoquinoxaline (1.05 g, 5.02 mMol), tetrakis(triphenylphosphine)palladium (0.232 g, 0.2 mMol), and lithium chloride (0.639 g, 15.1 mMol) in dry toluene (50 mL) under nitrogen was treated with tributylvinyl tin (4.4 mL, 15.1 mMol) and heated to one hundred degrees for three hours. After cooling to room temperature the mixture was partitioned between ethyl acetate (200 mL) and water (100 mL). The aqueous layer was discarded and the organics washed with brine (2×100 mL), dried with magnesium sulfate, filtered, and concentrated to dryness on a rotary evaporator. Purification by flash column chromatography on silica gel using 10% ethyl acetate in dichloromethane as eluant yielded 680 mg (87% yield) of 6-vinylquinoxaline as a light orange solid. 1H NMR (DMSO-d6): δ=8.92 (dd, 2H, J=14.1, 1.9 Hz), 8.10 (m, 3H), 7.03 (dd, 1H, J=17.7, 10.9 Hz), 6.15 (dd, 1H, J=17.7, 0.4Hz), 5.52 (d, 1H, J=11.1 Hz). LC/MS (Method A), rt=1.14 mins., purity=99%, calculated mass=156, [M+H]+=157.

Workup

  1. temperatureheated to one hundred degrees for three hours
  2. customwas partitioned between ethyl acetate (200 mL) and water (100 mL)
  3. washthe organics washed with brine (2×100 mL)
  4. dry with materialdried with magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated to dryness on a rotary evaporator
  7. customPurification by flash column chromatography on silica gel using 10% ethyl acetate in dichloromethane as eluant

Sources & evidence

ORD record
ord-2fb0a70835194ceb9f6de62abad7cee1
Source dataset
uspto-grants-2010_04
Patent number
US07696210B2

Reaction notes

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