1-Methyl-2(1H)-pyridinone → 1-Methyl-6-oxo-1,6-dihydropyridine-3-sulfonic acid, ammonium salt
Reaction equation
Cl[S:2]([OH:5])(=[O:4])=[O:3].[CH3:6][N:7]1[CH:12]=[CH:11][CH:10]=[CH:9][C:8]1=[O:13]>O>[NH4+:7].[CH3:6][N:7]1[C:8](=[O:13])[CH:9]=[CH:10][C:11]([S:2]([O-:5])(=[O:4])=[O:3])=[CH:12]1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 50 °C
Procedure
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.