Trifluoroacetic anhydride → 2-Chloro-4-nitropyridine 1-oxide

HRID 1875132Notes

Reaction equation

HRID 1875132 reaction equation
C(OC(C(F)(F)F)=O)(C(F)(F)F)=[O:2].[Cl:14][C:15]1[CH:20]=[C:19]([N+:21]([O-:23])=[O:22])[CH:18]=[CH:17][N:16]=1.OO.NC(N)=O>C(Cl)Cl>[Cl:14][C:15]1[CH:20]=[C:19]([N+:21]([O-:23])=[O:22])[CH:18]=[CH:17][N+:16]=1[O-:2]

Participants

5

Reactant 3

HCID 9845Trifluoroacetic anhydrideHCID 31294Carbamide PeroxideHCID 7351522-Chloro-4-nitropyridine

Product 1

HCID 844332-Chloro-4-nitropyridine 1-oxideYield 95%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

TFAA (6.15 ml, 43.5 mmol) was slowly added to a solution of 2-chloro-4-nitropyridine (3.45 g, 21.76 mmol) and urea hydrogen peroxide (4.30 g, 45.7 mmol) in CH2Cl2 at 0° C. under N2. The reaction was stirred for 30 min and then allowed to warm up to RT for 4 h. NH3 gas was bubbled into the mixture for 5 min and then the organic layer was washed with sat. NaHCO3, dried over Na2SO4, filtered and concentrated. The residue was purified by chromatography on silica gel eluted with 0-2% 2M NH3 solution of MeOH in CH2Cl2 to give the product as a light-yellow solid (3.59 g, 95%). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 8.39 (1H, d) 8.36 (1H, d) 8.04 (1H, dd). LCMS: m/z 175 (M+1).

Workup

  1. customNH3 gas was bubbled into the mixture for 5 min
  2. washthe organic layer was washed with sat. NaHCO3
  3. dry with materialdried over Na2SO4
  4. filtrationfiltered
  5. concentrationconcentrated
  6. customThe residue was purified by chromatography on silica gel
  7. washeluted with 0-2% 2M NH3 solution of MeOH in CH2Cl2

Sources & evidence

ORD record
ord-3123f4c400a7450db6fe873e9cdd17fd
Source dataset
uspto-grants-2012_11
Patent number
US08304419B2

Reaction notes

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