methyl 1-oxidopyridin-1-ium-4-carboxylate

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

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

Procedure: To a solution of methyl isonicotinate N-oxide (20.0 g, 0.26 mol) in 200 mL of methylene chloride was added trimethylsilyl cyanide (16.1 g, 0.32 mol), followed by a solution of dimethylcarbamyl chloride (17.82 g, 0.32 mol) in 50 mL of methylene chloride at room temperature. The reaction mixture was stirred overnight (about eighteen hours) and then treated with 500 mL of 10% potassium carbonate solution. The organic layer was washed with brine, dried over magnesium sulfate and filtered. The filtrate was concentrated to 15.2 g of crude product as a brown solid, which was used without further purification. The organic layer was washed with brine dried over magnesium sulfate filtered The filtrate was concentrated to 15.2 g of crude product as a brown solid, which was used without further purification

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of hydrogen peroxide (43 mL) in 250 mL of acetic acid was added methyl isonicotinate. The reaction mixture was stirred at 80° C. overnight (about eighteen hours). The solution was concentrated to about 50 mL, water was added and the mixture was saturated with sodium carbonate. The aqueous phase was extracted with methylene chloride. The organic layer was washed with brine, dried over magnesium sulfate and filtered. The filtrate was concentrated and trituated with hexane. The resulting precipitate was filtered and air-dried to give 24.5 g (65% yield) of product as a white solid: mp: 118-120° C. The solution was concentrated to about 50 mL, water was added The aqueous phase was extracted with methylene chloride The organic layer was washed with brine dried over magnesium sulfate filtered The filtrate was concentrated The resulting precipitate was filtered air-dried