Acetyl chloride → 4-Chloro-2,3,5-trimethyl-1-oxidopyridin-1-ium
Reaction equation
[CH3:1][C:2]1[C:7]([CH3:8])=[C:6]([N+]([O-])=O)[C:5]([CH3:12])=[CH:4][N+:3]=1[O-:13].C([Cl:17])(=O)C>>[Cl:17][C:6]1[C:5]([CH3:12])=[CH:4][N+:3]([O-:13])=[C:2]([CH3:1])[C:7]=1[CH3:8]Participants
3
Procedure
The 2,3,5-trimethyl-4-nitropyridine1-oxide (13.4 g, 73.6 mmol) obtained in the step (11c) was added to acetyl chloride (80 ml, 1,125 mmol) at −30° C. in a nitrogen atmosphere. The mixture was stirred at −30° C. to room temperature for 4 hours and 20 minutes. After the reaction mixture was concentrated, the residue was subjected to silica gel column chromatography (NH silica gel: 300 g, elution solvent: heptane, heptane/ethyl acetate=50/50, ethyl acetate, ethyl acetate/methanol=10/1) to obtain fractions containing a pure product of the title compound and fractions containing a crude product of the title compound.
Workup
- concentrationAfter the reaction mixture was concentrated
- washthe residue was subjected to silica gel column chromatography (NH silica gel: 300 g, elution solvent: heptane, heptane/ethyl acetate=50/50, ethyl acetate, ethyl acetate/methanol=10/1)