1-Methyl-2(1H)-pyridinone → 1-Methyl-6-oxo-1,6-dihydropyridine-3-sulfonic acid, ammonium salt

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Reaction Conditions

Reaction Steps

Chlorosulphonic acid (2 ml, 30.1 mmol) was added cautiously dropwise by pipette over 5 minutes to stirred neat 1-methylpyridin-2(1H)-one (8.09 ml, 82 mmol) and the resulting viscous solution was stirred at 50° C. for 40 hours. The cooled solidified reaction mixture was then added cautiously to water (100 ml), giving a clear brown solution. This solution was concentrated in vacuo to 40 ml, then made basic with concentrated ammonia solution, and washed with dichloromethane (6×100 ml). The aqueous phase was then evaporated to give a brown slurry which was triturated in methanol and filtered. The filtrate was evaporated to give 1-methyl-6-oxo-1,6-dihydropyridine-3-sulfonic acid, ammonium salt (3 g) as a brown solid. LCMS (Method F, ES-API): RT 0.46 min, m-H=188.0.

Provenance & Evidence