Trifluoroacetic anhydride → 2,6-dichloro-4-methyl-nicotinic acid-N-oxide

HRID 1711151Notes

Reaction equation

HRID 1711151 reaction equation
[Cl:1][C:2]1[N:10]=[C:9]([Cl:11])[CH:8]=[C:7]([CH3:12])[C:3]=1[C:4]([OH:6])=[O:5].C(N)(N)=[O:14].OO.FC(F)(F)C(OC(=O)C(F)(F)F)=O>C(Cl)Cl>[Cl:1][C:2]1[N+:10]([O-:14])=[C:9]([Cl:11])[CH:8]=[C:7]([CH3:12])[C:3]=1[C:4]([OH:6])=[O:5]

Participants

5

Reactant 3

HCID 9845Trifluoroacetic anhydrideHCID 31294Carbamide PeroxideHCID 6761212,6-Dichloro-4-methylpyridine-3-carboxylic acid

Product 1

HCID 866295192,6-dichloro-4-methyl-nicotinic acid-N-oxideYield 41%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

2,6-Dichloro-4-methyl-nicotinic acid (0.234 g, 1.14 mmol) and hydrogen peroxide-urea adduct (0.537 g, 5.70 mmol) were suspended in CH2Cl2 to give a white slurry. Trifluoroacetic anhydride (0.65 ml, 4.67 mmol) was added dropwise over 5 minutes and the resulting pale yellow solution was stirred overnight at rt. The reaction mixture was quenched with water (10 ml) and then dry loaded onto silica gel and purified using column chromatography (MeCN/MeOH/NH4OH, 8:1:1, v/v/v) to give 2,6-dichloro-4-methyl-nicotinic acid-N-oxide as a pale yellow crystalline solid (0.103 g, 41%). 1H NMR (CD3OD) δ 2.37 (s, 3H), 7.60 (s, 1H).

Workup

  1. customto give a white slurry
  2. customThe reaction mixture was quenched with water (10 ml)
  3. customdry
  4. custompurified

Sources & evidence

ORD record
ord-b5406a60f8f04922b3fbc74c06b42ece
Source dataset
uspto-grants-2010_09
Patent number
US07790747B2

Reaction notes

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