Iodine → 1-Quinoxalin-2-yl-but-3-yn-1-ol

HRID 1189222Notes

Reaction equation

HRID 1189222 reaction equation
[Mg].II.[CH2:4](Br)[C:5]#[CH:6].[N:8]1[C:17]2[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=2)[N:11]=[CH:10][C:9]=1[CH:18]=[O:19].[NH4+].[Cl-]>CCOCC.C1COCC1>[N:8]1[C:17]2[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=2)[N:11]=[CH:10][C:9]=1[CH:18]([OH:19])[CH2:6][C:5]#[CH:4]

Participants

8

Reactant 5

HCID 807IodineHCID 7842Propargyl bromideHCID 25517Ammonium ChlorideHCID 594088Quinoxaline-2-carbaldehydeHCID 5462224Magnesium

Product 1

HCID 866302471-Quinoxalin-2-yl-but-3-yn-1-olYield 14.2%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolvent2×HCID 8028TetrahydrofuranSolvent

Procedure

To a mixture of magnesium (229 mg, 9.41 mmol), mercuric chloride (13 mg, 47 mmol) and few crystals of iodine in Et2O (1.5 mL), a solution of propargyl bromide (0.53 mL, 5.88 mmol) in Et2O (4.5 mL) was added slowly in order to maintain a reflux. The reaction mixture was stirred 1 hour and added to a solution of quinoxaline-2-carbaldehyde (500 mg, 3.16 mmol) in THF (2 mL). The resulting reaction mixture was stirred at 0° C. for 30 min., at room temperature for 30 min. and was poured onto saturated NH4Cl solution. The aqueous phase was extracted with Et2O. The aqueous phase was washed with water, brine, dried over MgSO4, filtered and evaporated. The crude residue was purified by C18 flash chromatography (H2O/acetonitrile 100:0 to 80:20) to yield 90 mg (0.45 mmol, 14%) of 1-quinoxalin-2-yl-but-3-yn-1-ol as a yellow oil.

Workup

  1. temperatureto maintain a reflux
  2. customThe resulting reaction mixture
  3. stirringwas stirred at 0° C. for 30 min., at room temperature for 30 min.
  4. extractionThe aqueous phase was extracted with Et2O
  5. washThe aqueous phase was washed with water, brine
  6. dry with materialdried over MgSO4
  7. filtrationfiltered
  8. customevaporated
  9. customThe crude residue was purified by C18 flash chromatography (H2O/acetonitrile 100:0 to 80:20)

Sources & evidence

ORD record
ord-ce6953db6b5c48209d7b48b0621b6d01
Source dataset
uspto-grants-2014_03
Patent number
US08674106B2

Reaction notes

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