Methylparaben → Benzoic acid, 4-[(1-methyl-4-piperidinyl)oxy]-, methyl ester

Participants

Reaction Steps

To a solution of 1-methyl-piperidin-4-ol (6.8 g. 59 mmoles), PPh3 (triphenylphosphine, 15.5 g, 59 mmoles) and 4-hydroxy-benzoic acid methyl ester (6 g, 39 mmoles) in THF (150 ml) at 0° C., diethyl azodicarboxylate (9.5 ml, 59 mmoles) in THF (30 ml) was slowly added. The reaction mixture was allowed to warm to room temperature over a period of 24 hours. It was then evaporated and the residue redissolved in 5% aqueous citric acid (700 ml). The solution was washed with ethyl acetate (3×250 ml), made alkaline with concentrated NH4OH (pH˜8) and then extracted with dichloromethane (3×250 ml). The combined dichloromethane extracts were washed with brine, dried and evaporated to give an oil which was purified by flash chromatography on silica gel using dichloromethane-MeOH (90:10) as eluent, to give the title compound as a yellow oil (7.4 g, 75%).

Provenance & Evidence