Potassium Carbonate → 4-Butyl-6,7-dichloro-2,3-dihydro-pyrazino(2,3-b)(1,4)oxazine

HRID 437027Notes

Reaction equation

HRID 437027 reaction equation
Cl[C:2]1[N:7]=[C:6]([Cl:8])[C:5]([Cl:9])=[N:4][C:3]=1Cl.[CH2:11]([NH:15][CH:16](O)[CH3:17])[CH2:12][CH2:13][CH3:14].C(=O)([O-])[O-:20].[K+].[K+].[OH-].[K+]>O1CCOCC1.O>[CH2:11]([N:15]1[CH2:16][CH2:17][O:20][C:3]2[N:4]=[C:5]([Cl:9])[C:6]([Cl:8])=[N:7][C:2]1=2)[CH2:12][CH2:13][CH3:14]

Participants

7

Reactant 4

HCID 11430Potassium CarbonateHCID 14797Potassium HydroxideHCID 311820TetrachloropyrazineHCID 180042651-(Butylamino)ethanol

Product 1

HCID 214299384-Butyl-6,7-dichloro-2,3-dihydro-pyrazino(2,3-b)(1,4)oxazineYield 48%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Procedure

A mixture of tetrachloropyrazine (21.8 g, 0.1 mol), n-butylaminoethanol (11.7 g, 0.1 mol), and potassium carbonate (28 g, 0.2 mol) were heated to 80° in 225 ml of dioxane and 50 ml of water for 24 hours. After extraction with CH2Cl2 and concentration with rotary evaporation, 30 g of an oil characterized by nmr as the N-substituted product was obtained. An attempt to distill 5 g of this material led to decomposition. The rest of the material was dissolved in 200 ml of benzene and refluxed for 2 hours with crushed KOH (10 g, 85% assay, 0.15 mol). The mixture was partitioned between water and CH2Cl2. The organic layer was dried (MgSO4) and rotary evaporated to give a crude oil. This was distilled two times on a Kugelrohr apparatus (b.p. about 130° at 0.5 mm Hg) to give 12.5 g (48% yield) of the title product.

Workup

  1. extractionAfter extraction
  2. concentrationwith CH2Cl2 and concentration
  3. customwith rotary evaporation, 30 g of an oil
  4. customwas obtained
  5. distillationAn attempt to distill 5 g of this material
  6. dissolutionThe rest of the material was dissolved in 200 ml of benzene
  7. customThe mixture was partitioned between water and CH2Cl2
  8. dry with materialThe organic layer was dried (MgSO4)
  9. customrotary evaporated
  10. customto give a crude oil
  11. distillationThis was distilled two times on a Kugelrohr apparatus (b.p. about 130° at 0.5 mm Hg)

Sources & evidence

ORD record
ord-322ae456d5834b338e68f7103f181c97
Source dataset
uspto-grants-1977_06
Patent number
US04029657

Reaction notes

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