Pyridine → 3-(Bromomethyl)-1-methylpiperidine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

3-(Hydroxymethyl)-1-methylpiperidine (2 g, 15.5 mmoles) was dissolved in anhydrous acetonitrile (32 mL) and anhydrous pyridine (2.02 mL, 24.8 mmoles) was added and the solution was cooled to 0° C. Dibromotriphenylphosphorane (8.49 g, 20.2 mmoles) was added at 0° C. and the mixture was allowed to warm up to 25° C. and was stirred for 94 h. The mixture was evaporated to dryness and the residue was chromatographed on a silica gel column (30×5 cm) using gradient elution with dichloromethane, 35% diethyl ether in dichloromethane and 5–10% methanol in dichloromethane as the eluant to give 3-(bromomethyl)-1-methylpiperidine (3.13 g, 100%): FABMS: m/z 192.1 (MH+); δH (CDCl3) 1.52 (1H, m, CH2), 1.99 (2H, m, CH2), 2.43 (1H, m, CH2), 2.75 (2H, m, CH2), 2.82 (1H, m CH), 2.86/2.88 (3H, s, NCH3), 3.42/3.49 (2H, dd, —CH2Br) and 3.56 ppm (2H, m, CH2); δC (CDCl3) CH3: 44.3; CH2: 22.1, 26.6, 35.4, 54.8, 58.2; CH: 34.6.

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