反应详情

A mixture of 1-benzyl-4-(4-methoxy)phenylpiperidine (XVIII, Step 3, 0.4724 g, 1.7 mmol), dichloroethane (4.4 ml) and 1-chloroethylchloroformate (0.66 ml, 6.1 mmol) is refluxed overnight, then concentrated and the residue refluxed in methanol for 2 hours. After cooling, the solvent is removed and the resulting solids are slurried in dichloromethane. Ether is added and the solids are collected and then partitioned between dichloromethane and saturated sodium bicarbonate. The combined organic phases are backwashed with saline, dried over magnesium sulfate, and concentrated to give a residue which is chromatographed on silica gel eluting with methanol/dichloromethane (4/96) containing ammonium hydroxide (0.4%), followed by methanol/dichloromethane (6/94) containing ammonium hydroxide (0.4%). The appropriate fractions are pooled and concentrated to give 4-(4-methoxyphenyl)piperidine (XIX), NMR (CDCl3) 1.66, 1.83, 2.06, 2.58, 2.76, 3.21, 3.79. 6.85 and 7.15 δ.

1. temperatureis refluxed overnight
2. concentrationconcentrated
3. temperaturethe residue refluxed in methanol for 2 hours
4. temperatureAfter cooling
5. customthe solvent is removed
6. additionEther is added
7. customthe solids are collected
8. custompartitioned between dichloromethane and saturated sodium bicarbonate
9. dry with materialdried over magnesium sulfate
10. concentrationconcentrated
11. customto give a residue which
12. customis chromatographed on silica gel eluting with methanol/dichloromethane (4/96)
13. additioncontaining ammonium hydroxide (0.4%)
14. additioncontaining ammonium hydroxide (0.4%)
15. concentrationconcentrated