反应详情

温度

-78 °C

To a solution of ethyl 1-benzylpiperidine-4-carboxylate (9.2 g, 0.037 mol) in 400 ml of toluene was added 1.5M diisobutylaluminum hydride in toluene (28 ml, 0. 042 mol) at -78° C. The mixture was stirred at -78° C. for 1 hr and quenched with 150 ml of MeOH and the dry ice bath was removed. After stirring for 2 hr at r.t., the mixture was filtered through diatomaceous earth (Celite (trademark)) and washed with methanol. The filtrate was concentrated to dryness to give 6.91 g (92%) of 1-benzylpiperidine-4-carboxaldehyde which can be used directly or purified by vacuum distillation, bp 93°-97° C./1 mmHg. HNMR (CDCl3)δ 1.6-1.8 (m, 2H), 1.8-1.9 (m, 2H), 2.05-2.17 (m, 2H), 2.17-2.3 (m, 1H), 2.75-2.9 (m, 2H), 3.5 (s, 2H), 7.2-7.4 (m, 5H), 9.6 (s, 1H) ppm.

1. customquenched with 150 ml of MeOH
2. customthe dry ice bath was removed
3. stirringAfter stirring for 2 hr at r.t.
4. filtrationthe mixture was filtered through diatomaceous earth (Celite (trademark))
5. washwashed with methanol
6. concentrationThe filtrate was concentrated to dryness