1,1-Dichloroethane → 4-(4-Methoxyphenyl)-1,2,3,6-tetrahydropyridine
Reaction equation
C([N:8]1[CH2:13][CH:12]=[C:11]([C:14]2[CH:19]=[CH:18][C:17]([O:20][CH3:21])=[CH:16][CH:15]=2)[CH2:10][CH2:9]1)C1C=CC=CC=1.ClC(Cl)C.ClC(OC(Cl)=O)C>>[CH3:21][O:20][C:17]1[CH:16]=[CH:15][C:14]([C:11]2[CH2:12][CH2:13][NH:8][CH2:9][CH:10]=2)=[CH:19][CH:18]=1Participants
4
Procedure
A mixture of 1-benzyl-1,2,3,6-tetrahydro-4-(4-methoxyphenyl)pyridine (XVI, EXAMPLE 42--Step 2, 2.021 g, 7.2 mmol), dichloroethane (19 ml) and 1-chloroethylchloroformate (2.8 ml, 26.0 mmol) is refluxed overnight. The mixture is concentrated to about one third the original volume and methanol is added. The mixture is refluxed for 2 hr, then cooled and concentrated. The resulting solids are slurried in dichloromethane, ether is added, and the solids are collected and then partitioned between dichloromethane and saturated aqueous sodium bicarbonate. Some solids remained in the aqueous phase and are collected and combined with the organic fractions. Following chromatography on silica gel eluting with methanol/dichloromethane (0.5% ammonium hydroxide, 6/94), the appropriate fractions are pooled and concentrated to give 1,2,3,6-tetrahydro-4-(4-methoxypheny)pyridine (XVII).