[Br:1][C:2]1[N:7]=[C:6]([CH:8]=O)[CH:5]=[CH:4][CH:3]=1.[NH:10]1[CH2:15][CH2:14][CH2:13][CH2:12][CH2:11]1.C(O)(=O)C.C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+].C(=O)([O-])O.[Na+]>ClCCl>[Br:1][C:2]1[CH:3]=[CH:4][CH:5]=[C:6]([CH2:8][N:10]2[CH2:15][CH2:14][CH2:13][CH2:12][CH2:11]2)[N:7]=1To a solution of 6-bromopyridine-2-carbaldehyde (25 g, 135 mmol) in dichloromethane (500 ml) was slowly added piperidine (12.6 g, 149 mmol) at 10° C. After stirring for 15 minutes at 10° C., acetic acid (8.9 g, 149 mmol) was added, followed by the portionwise addition of sodium triacetoxyborohydride, while the temperature was kept at 5-10° C. After stirring for 2 h at room temperature the reaction mixture was poured into a saturated aqueous solution of sodium hydrogen carbonate. The product was extracted into dichloromethane and the combined organic phases were washed with brine, dried over sodium sulphate and concentrated under reduced pressure. Column chromatography afforded 2-bromo-6-(piperidin-1-ylmethyl)pyridine (30 g) as a colourless oil.
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