Borane;tetrahydrofuran → 1-Cyclopropyl-1,2,3,4-tetrahydroquinoxaline

HRID 1966976Notes

Reaction equation

HRID 1966976 reaction equation
[CH:1]1([N:4]2[C:13]3[C:8](=[CH:9][CH:10]=[CH:11][CH:12]=3)[NH:7][C:6](=O)[C:5]2=O)[CH2:3][CH2:2]1.B.O1CCCC1>O1CCCC1>[CH:1]1([N:4]2[C:13]3[C:8](=[CH:9][CH:10]=[CH:11][CH:12]=3)[NH:7][CH2:6][CH2:5]2)[CH2:3][CH2:2]1

Participants

4

Reactant 2

HCID 2723981Borane;tetrahydrofuranHCID 212796951-Cyclopropyl-1,4-dihydroquinoxaline-2,3-dione

Product 1

HCID 673207551-Cyclopropyl-1,2,3,4-tetrahydroquinoxalineYield 49%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a stirred suspension of 1-cyclopropyl-1,4-dihydro-quinoxaline-2,3-dione (10.0 g, 49.45 mmol, 1.0 equiv) in tetrahydrofuran (500 mL) was added dropwise a 1 M solution of borane-tetrahydrofuran complex (108.8 mL, 108.8 mmol, 2.2 equiv; [CAS RN 14044-65-6]) and the reaction mixture stirred at room temperature over night. The solvent was removed by evaporation under reduced pressure and the crude reaction mixture extracted from a saturated aqueous solution of sodium bicarbonate (100 mL) with ethyl acetate (three times 100 mL). The combined organic phases were dried over sodium sulfate and purified by silica gel column chromatography using a MPLC system (CombiFlash Companion, Isco Inc.) eluting with a gradient of n-heptane:ethyl acetate to give 4.2 g (49%) of the title compound as a light yellow solid. MS (ISP): m/z=175.4 [M+H]+.

Workup

  1. customThe solvent was removed by evaporation under reduced pressure
  2. customthe crude reaction mixture
  3. extractionextracted from a saturated aqueous solution of sodium bicarbonate (100 mL) with ethyl acetate (three times 100 mL)
  4. dry with materialThe combined organic phases were dried over sodium sulfate
  5. custompurified by silica gel column chromatography
  6. washeluting with a gradient of n-heptane

Sources & evidence

ORD record
ord-2a9d5eaa5055494792b92eb6a092c9d4
Source dataset
uspto-grants-2013_04
Patent number
US08420647B2

Reaction notes

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