(Dimethyl sulfide)trihydroboron → Methyl 4-butyl-1,2,3,4-tetrahydroquinoxaline-6-carboxylate

HRID 14200Notes

Reaction equation

HRID 14200 reaction equation
[CH2:1]([N:5]1[C:14]2[C:9](=[CH:10][CH:11]=[C:12]([C:15]([O:17][CH3:18])=[O:16])[CH:13]=2)[NH:8][CH2:7][C:6]1=O)[CH2:2][CH2:3][CH3:4].CSC.B>O1CCCC1>[CH2:1]([N:5]1[C:14]2[C:9](=[CH:10][CH:11]=[C:12]([C:15]([O:17][CH3:18])=[O:16])[CH:13]=2)[NH:8][CH2:7][CH2:6]1)[CH2:2][CH2:3][CH3:4]

Participants

4

Reactant 2

HCID 12423031(Dimethyl sulfide)trihydroboronHCID 21086199Methyl 4-butyl-3-oxo-1,2,3,4-tetrahydroquinoxaline-6-carboxylate

Product 1

HCID 21086196Methyl 4-butyl-1,2,3,4-tetrahydroquinoxaline-6-carboxylateYield 45.8%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To an ice-cold, stirred solution of methyl 4-butyl-3-oxo-1,2,3,4-tetrahydroquinoxaline-6-carboxylate (840 mg) in tetrahydrofuran (32 mL) was added borane dimethylsulfide complex (3.2 mL, 2.0 M tetrahydrofuran) and the resulting mixture was refluxed for 24 h. The mixture was cooled to room temperature, quenched with methanol, and the solvent was removed under reduced pressure. Purification by flash column chromatography (silica, 1:1 ethyl acetate/hexanes) provided 364 mg of the title compound: 1H NMR (300 MHz, CDCl3) δ 7.27, 7.22, 6.41, 3.84, 3.47-3.45, 3.32-3.23, 1.60-1.58, 1.42-1.37, 0.99-0.94.

Workup

  1. temperaturethe resulting mixture was refluxed for 24 h
  2. customquenched with methanol
  3. customthe solvent was removed under reduced pressure
  4. customPurification by flash column chromatography (silica, 1:1 ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-b80f3cf61c3b43018eeef01983796dc0
Source dataset
uspto-grants-2010_06
Patent number
US07727997B2

Reaction notes

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