Sulfuric Acid → 3-Bromo-4-chloro-2,6-dimethylpyridine
Reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([CH3:8])[N:5]=[C:4]([CH3:9])[CH:3]=1.FC(F)(F)C(O)=O.S(=O)(=O)(O)O.C1C(=O)N([Br:29])C(=O)C1.[OH-].[Na+]>>[Br:29][C:3]1[C:4]([CH3:9])=[N:5][C:6]([CH3:8])=[CH:7][C:2]=1[Cl:1]Participants
6
Procedure
4-chloro-2,6-dimethylpyridine (1.5 g) was added to a mixed solvent of trifluoroacetic acid (3 mL) and concentrated sulfuric acid (6 mL). NBS (22 g) was added to the solution, and the mixture was stirred at room temperature for 12 hours. A 5 N aqueous sodium hydroxide solution was added to the reaction mixture, followed by separation with ethyl acetate. The organic layer was washed with brine and then dried over anhydrous magnesium sulfate. The desiccant was removed by filtration, and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (ethyl acetate/n-heptane, 5% to 30%) to give the title compound (500 mg).
Workup
- customfollowed by separation with ethyl acetate
- washThe organic layer was washed with brine
- dry with materialdried over anhydrous magnesium sulfate
- customThe desiccant was removed by filtration
- concentrationthe filtrate was concentrated under reduced pressure
- customThe resulting residue was purified by silica gel column chromatography (ethyl acetate/n-heptane, 5% to 30%)
Sources & evidence
- ORD record
- ord-e41be24f0a274bd5b52c552b0224499c
- Source dataset
- uspto-grants-2013_10
- Patent number
- US08563565B2
Reaction notes
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