Formaldehyde → 4-Benzyloxy-2,6-diethyl-1,2,3,6-tetramethylpiperidine

Reaction equation

[CH2:1]([O:8][CH:9]1[CH2:14][C:13]([CH2:16][CH3:17])([CH3:15])[NH:12][C:11]([CH2:19][CH3:20])([CH3:18])[CH:10]1[CH3:21])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C=O.[C:24](=O)(O)[O-].[Na+]>C(O)=O>[CH2:1]([O:8][CH:9]1[CH2:14][C:13]([CH2:16][CH3:17])([CH3:15])[N:12]([CH3:24])[C:11]([CH2:19][CH3:20])([CH3:18])[CH:10]1[CH3:21])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

Procedure

To 1.0 g of 4-benzyloxy-2,6-diethyl-2,3,6-trimethylpiperidine (Compound 95 - prepared as described in Preparation 5) were added 0.52 g of formic acid and 1.22 g of 37 % formalin at 0° - 5° C. The mixture was stirred at room temperature and then refluxed by heating for 3 hours. When the reaction was complete, the reaction mixture was adjusted to a pH value of 8.0 by addition of a 5 % aqueous solution of sodium bicarbonate; the mixture was then extracted with ethyl acetate. The extract was dried over anhydrous magnesium sulphate and the solvent was removed by evaporation under reduced pressure. The residue was purified by column chromatography on silica gel using benzene as eluent; the resulting product was then distilled under reduced pressure, giving 0.6 g of Compound 100 as a pale yellow liquid (bp 132° - 135° C/0.2 mmHg).