[Br:1]Br.[N:3]1([C:9]2[CH:14]=[CH:13][N:12]=[C:11]([CH3:15])[CH:10]=2)[CH2:8][CH2:7][CH2:6][CH2:5][CH2:4]1.C(=O)([O-])[O-].[K+].[K+]>CN(C)C=O.O>[N:3]1([C:9]2[C:14]([Br:1])=[CH:13][N:12]=[C:11]([CH3:15])[CH:10]=2)[CH2:4][CH2:5][CH2:6][CH2:7][CH2:8]1A solution of bromine (9.3 ml) in dimethylformamide (50 ml) was added dropwise-to a stirred mixture of 4 -piperidino-2 -picoline (15 g), potassium carbonate (23.5. g) in dimethylformamide (50 ml) at 25°-30°. After 3.5 hours, the mixture was stripped and the residue taken up in water, adjusted to pH 13 with 40 % aqueous NAOH, and extracted with ether. After drying (K2CO3 ) and stripping, the residue was chromatographed (silica gel, n-hexane:ether) to give 4 -piperidino-5 -bromo-2 -picoline, 11.18 g, as an oil and 4 -piperidino-3 -bromo-2 -picoline, 3.5 g, as an oil.
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