Nitric Acid → 2,3-Dimethyl-4-nitropyridine-N-oxide

Reaction equation

[CH3:1][C:2]1[C:7]([CH3:8])=[CH:6][CH:5]=[CH:4][N+:3]=1[O-:9].[N+:10]([O-])([OH:12])=[O:11].C(=O)([O-])[O-].[Na+].[Na+]>S(=O)(=O)(O)O>[CH3:1][C:2]1[C:7]([CH3:8])=[C:6]([N+:10]([O-:12])=[O:11])[CH:5]=[CH:4][N+:3]=1[O-:9]

Participants

Procedure

A solution of 183 mg (1.49 mmol) of 2,3-dimethylpyridine 1-oxide in 0.6 ml of conc. sulphuric acid is treated while coollng with ice with 0.2 ml of 65% nitric acid (d=1.4). The reaction mixture is stirred at 9° for 24 hours and poured on to a mixture of ice and sodium carbonate, whereupon the resulting mixture is extracted with methylene chloride and the methylene chloride phase is dried and evaporated. The residue crystallized from ethanol/n-pentane, gives 2,3-dimethyl-4-nitropyridine 1-oxide of melting point 99°-102°.