Sodium Carbonate → 2-[4-(Trifluoromethyl)phenyl]pyrazine

HRID 1869768Notes

Reaction equation

HRID 1869768 reaction equation
Cl[C:2]1[CH:7]=[N:6][CH:5]=[CH:4][N:3]=1.[F:8][C:9]([F:20])([F:19])[C:10]1[CH:15]=[CH:14][C:13](B(O)O)=[CH:12][CH:11]=1.C(=O)([O-])[O-].[Na+].[Na+]>O1CCOCC1.[Cl-].[Cl-].C1(P([C-]2C=CC=C2)C2C=CC=CC=2)C=CC=CC=1.[CH-]1C=CC=C1.[Fe+2].[Pd+2]>[F:8][C:9]([F:20])([F:19])[C:10]1[CH:15]=[CH:14][C:13]([C:2]2[CH:7]=[N:6][CH:5]=[CH:4][N:3]=2)=[CH:12][CH:11]=1

Participants

6

Reactant 3

HCID 10340Sodium CarbonateHCID 73277ChloropyrazineHCID 27343894-(Trifluoromethyl)phenylboronic acid

Product 1

HCID 50458142-[4-(Trifluoromethyl)phenyl]pyrazine

Reagents, catalysts & solvents 2

HCID 178478644HCID 178478644, compoundCatalystHCID 312751,4-DioxaneSolvent

Procedure

A mixture of chloropyrazine (10, 0.087 mol), 4-(trifluoromethyl)phenylboronic acid (21 g), palladium(diphenylphosphino)ferrocene dichloride (3.5 g, 5 mol %) and sodium carbonate (100 mL, 2M) in dioxane (200 mL) was degassed (×3) via Firestone valve. The mixture was heated under reflux for 1 h., evaporated in vacuo, the residue partitioned between ethyl acetate and water, then the organic phase was washed with brine, dried (MgSO4) and evaporated. The black residue was dry-loaded onto silica and purified by elution with 5-25% ethyl acetate in iso-hexane. This afforded the product as white crystals.

Workup

  1. customwas degassed (×3) via Firestone valve
  2. temperatureThe mixture was heated
  3. temperatureunder reflux for 1 h.
  4. customevaporated in vacuo
  5. customthe residue partitioned between ethyl acetate and water
  6. washthe organic phase was washed with brine
  7. dry with materialdried (MgSO4)
  8. customevaporated
  9. custompurified by elution with 5-25% ethyl acetate in iso-hexane

Sources & evidence

ORD record
ord-a764eaa7aee84b359078935a8acc89f5
Source dataset
uspto-grants-2009_12
Patent number
US07638629B2

Reaction notes

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