Ethyl Acetate → 1,2,3,4-Tetrahydroquinoxaline

HRID 1886124Notes

Reaction equation

HRID 1886124 reaction equation
[H-].[Al+3].[Li+].[H-].[H-].[H-].O=[C:8]1[CH:17]=[N:16][C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[NH:9]1.C(OC(=O)C)C>C1COCC1>[NH:9]1[C:10]2[C:15](=[CH:14][CH:13]=[CH:12][CH:11]=2)[NH:16][CH2:17][CH2:8]1

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 145262(1H)-QuinoxalinoneHCID 21226445Aluminium lithium hydride3×

Product 1

HCID 770281,2,3,4-TetrahydroquinoxalineYield 66%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

Basically, a 500 ml, three-necked flask was charged with lithium aluminum hydride (300 Ml, 1M in THF, 300 mmol) under an inert atmosphere. To the lithium aluminum hydride was added 2-keto-1,2-dihydroquinoxaline (22 g, 0.15 mol) in dry THF (100 ml) in small portions to prevent a sharp rise of temperature. After the addition was complete, the mixture was heated at the refluxing temperature of THF for 4 hours. The excess lithium aluminum hydride was decomposed by a slow addition of ethylacetate (10 ml) at room temperature. The resulting mixture was dropped slowly into ice water and extracted with diethyl ether. The diethyl ether solution was dried over anhydrous MgSO4, filtered and the solvent evaporated to give a yellow solid. The solid was recrystallized in hexane to give 1,2,3,4-tetrahydroquinoxaline in 66% yield.

Workup

  1. additionAfter the addition
  2. extractionextracted with diethyl ether
  3. dry with materialThe diethyl ether solution was dried over anhydrous MgSO4
  4. filtrationfiltered
  5. customthe solvent evaporated
  6. customto give a yellow solid
  7. customThe solid was recrystallized in hexane

Sources & evidence

ORD record
ord-3b5add2cf5ef40468ff21de65ee9d973
Source dataset
uspto-grants-1992_09
Patent number
US05149773

Reaction notes

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