1-oxido-2-(trifluoromethyl)pyridin-1-ium

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 5.1 g (35 mmol) of trifluoromethylpyridine were dissolved at room temperature in 100 ml of dry dichloromethane, admixed with 17.3 g of m-chloroperbenzoic acid and stirred at room temperature for 72 h. Thereafter, the mixture was admixed with 1 N sodium hydroxide solution and extracted four times with dichloromethane; the combined organic phases were dried over magnesium sulfate, filtered and concentrated under reduced pressure. The crude product was taken up in water, stirred and filtered, and the filtrate was concentrated under reduced pressure. 65.3 was obtained in 47% yield. 1H NMR: 8.46, d, 1H, 7.96, d, 1H, 7.7, m, 1H, 7.5, m, 1H. extracted four times with dichloromethane the combined organic phases were dried over magnesium sulfate filtered concentrated under reduced pressure stirred filtered the filtrate was concentrated under reduced pressure 65.3 was obtained in 47% yield

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 5.1 g (35 mmol) of trifluoromethylpyridine were dissolved at room temperature in 100 ml of dry dichloromethane, admixed with 17.3 g of m-chloroperbenzoic acid and stirred at room temperature for 72 h. Thereafter, the mixture was admixed with 1 N sodium hydroxide solution and extracted four times with dichloromethane; the combined organic phases were dried over magnesium sulfate, filtered and concentrated under reduced pressure. The crude product was taken up in water, stirred and filtered, and the filtrate was concentrated under reduced pressure. 65.3 was obtained in 47% yield. 1H NMR: 8.46, d, 1H, 7.96, d, 1H, 7.7, m, 1H, 7.5, m, 1H. extracted four times with dichloromethane the combined organic phases were dried over magnesium sulfate filtered concentrated under reduced pressure stirred filtered the filtrate was concentrated under reduced pressure 65.3 was obtained in 47% yield

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 2-trifluoromethyl-pyridine 1-oxide (0.43 g, 2.43 mmol) in concentrated H2SO4 (2 mL) is added 70% HNO3 (1.6 mL) dropwise at 0° C. Reaction mixture is allowed to stir for 2 h at 130° C. After completion of reaction it is quenched with ice (˜200 g) and pH is adjusted 7 with solid K2CO3 (15-20 g) and extracted with EtOAc (3×20 mL). Organic part is washed with water, brine and dried over anhydrous MgSO4. Solution is concentrated under reduced pressure. The residue is purified by column chromatography (silica-gel, 100-200 mesh, eluent; 20% EtOAc in hexane) to afford 4-nitro-2-trifluoromethyl-pyridine 1-oxide (0.1 g, 20%). Reaction mixture After completion of reaction it is quenched with ice (˜200 g) and pH extracted with EtOAc (3×20 mL) Organic part is washed with water, brine dried over anhydrous MgSO4 Solution is concentrated under reduced pressure The residue is purified by column chromatography (silica-gel, 100-200 mesh, eluent; 20% EtOAc in hexane)

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 2-trifluoromethyl pyridine (5 g, 34 mmol) in acetic acid (25 mL) is added 33% of aqueous H2O2 (20 mL) at room temperature. The reaction mixture is allowed to stir for 12 h at 70° C. After complete consumption of starting material the reaction mixture is concentrated under reduced pressure. The residue is dissolved in chloroform (250 mL) and pH is adjusted to 7 with K2CO3 (20 g approx). Resulting solid is filtered through glass sintered funnel and washed with chloroform. Filtrate is concentrated under reduced pressure to give 2-trifluoromethyl-pyridine 1-oxide as syrupy liquid (4.3 g). After complete consumption of starting material the reaction mixture is concentrated under reduced pressure The residue is dissolved in chloroform (250 mL) Resulting solid is filtered through glass sintered funnel washed with chloroform Filtrate is concentrated under reduced pressure