Hydrochloric Acid → 2,3,4,4a-Tetrahydro-6-methyl-1H-pyrazino[1,2-a]quinoxalin-5(6H)-one

HRID 2052113Notes

Reaction equation

HRID 2052113 reaction equation
[H-].[Na+].C([N:13]1[CH2:27][CH2:26][N:16]2[C:17]3[C:22]([NH:23][C:24](=[O:25])[CH:15]2[CH2:14]1)=[CH:21][CH:20]=[CH:19][CH:18]=3)(OCC1C=CC=CC=1)=O.[CH3:28]I.Cl.[H][H]>[Pd].C(O)C.O.CN(C)C=O>[CH3:28][N:23]1[C:22]2[C:17](=[CH:18][CH:19]=[CH:20][CH:21]=2)[N:16]2[CH2:26][CH2:27][NH:13][CH2:14][CH:15]2[C:24]1=[O:25]

Participants

10

Reactant 5

HCID 313Hydrochloric AcidHCID 6328Methyl iodideHCID 24758Sodium hydrideHCID 121096443-benzyloxycarbonyl-2,3,4,4a-tetrahydro-1H-pyrazino[1,2-a]quinoxalin-5(6H)-oneHCID 178418361HCID 178418361, compound

Product 1

HCID 183773372,3,4,4a-Tetrahydro-6-methyl-1H-pyrazino[1,2-a]quinoxalin-5(6H)-one

Reagents, catalysts & solvents 4

HCID 23938PalladiumCatalystHCID 702EthanolSolventHCID 962WaterSolventHCID 6228DimethylformamideSolvent2×

Procedure

To a stirred suspension of 0.87 g. (0.0180 mole) of sodium hydride (50% suspension in nujol) in 50 ml. of dimethyl formamide under a nitrogen atmosphere is added 5.5 g. (0.968 mole) of 3-carbobenzoxy-2,3,4,4a-tetrahydro-1H-pyrazino[1,2-a]quinoxaline-5(6H)-one. The mixture is stirred 1/2 hours, then to it is added 4.5 g. of methyl iodide in 10 ml. of dimethylformamide. The resultant mixture is stirred for 1 hour, then poured into 100 ml. of water. The aqueous mixture is extracted with methylene chloride, dried (MgSO4) and concentrated to give 5.7 g. of viscous glass. This glass is dissolved in 150 ml. of ethanol containing 0.3 g. of hydrogen chloride and hydrogenated over 5 g. of 10% palladium on carbon for 51/2 hours at 45 p.s.i. hydrogen pressure with the temperature about 50°. The catalyst is filtered and the filtrate is concentrated. Recrystallization of the residue from ethanol gives 1.9 g. of product as the hydrochloride salt, m.p. 260°-264°.

Workup

  1. additionTo a stirred suspension of 0.87 g
  2. additionto it is added 4.5 g
  3. additionpoured into 100 ml
  4. extractionThe aqueous mixture is extracted with methylene chloride
  5. dry with materialdried (MgSO4)
  6. concentrationconcentrated
  7. customto give 5.7 g
  8. dissolutionThis glass is dissolved in 150 ml
  9. custom2 hours
  10. customwith the temperature about 50°
  11. filtrationThe catalyst is filtered
  12. concentrationthe filtrate is concentrated
  13. customRecrystallization of the residue from ethanol
  14. customgives 1.9 g

Sources & evidence

ORD record
ord-861ced896bee41bc8a8b575908ab116a
Source dataset
uspto-grants-1980_01
Patent number
US04182872

Reaction notes

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