Trifluoroacetic anhydride → 5-Chloro-3-(methoxycarbonyl)-2-methylpyrazine 1-oxide

HRID 627690Notes

Reaction equation

HRID 627690 reaction equation
[Cl:1][C:2]1[N:7]=[C:6]([C:8]([O:10][CH3:11])=[O:9])[C:5]([CH3:12])=[N:4][CH:3]=1.C(N)(N)=[O:14].OO.FC(F)(F)C(OC(=O)C(F)(F)F)=O>ClCCl>[Cl:1][C:2]1[N:7]=[C:6]([C:8]([O:10][CH3:11])=[O:9])[C:5]([CH3:12])=[N+:4]([O-:14])[CH:3]=1

Participants

5

Reactant 3

HCID 9845Trifluoroacetic anhydrideHCID 31294Carbamide PeroxideHCID 57992035Methyl 6-chloro-3-methylpyrazine-2-carboxylate

Product 1

HCID 867281445-Chloro-3-(methoxycarbonyl)-2-methylpyrazine 1-oxideYield 95%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a solution of methyl 6-chloro-3-methylpyrazine-2-carboxylate (8.6 g, 46.1 mmol) and hydrogen peroxide urea adduct (8.1 g, 86 mmol) in dichloromethane (100 mL) was added 2,2,2-trifluoroacetic anhydride (10.9 ml, 78 mmol) dropwise. The resulting mixture was stirred at room temperature for 2 h. The reaction mixture was diluted with DCM and quenched with water. The aqueous layer was extracted with DCM. The combined organic extracts were dried (MgSO4), filtered and concentrated in vacuo to give the crude product 5-chloro-3-(methoxycarbonyl)-2-methylpyrazine 1-oxide (8.83 g, 43.6 mmol, 95% yield) which was used without further purification. 1H NMR (300 MHz, CDCl3) δ ppm 8.31 (1H, s), 4.02 (3H, s), 2.65 (3H, s).

Workup

  1. customquenched with water
  2. extractionThe aqueous layer was extracted with DCM
  3. dry with materialThe combined organic extracts were dried (MgSO4)
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-744bd9f5361c4e71aefcf0cae120cc6f
Source dataset
uspto-grants-2016_04
Patent number
US09309263B2

Reaction notes

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