P-Cresol → Tolterodine

Participants

Reaction Conditions

Reaction Steps

10.2 g of N,N-diisopropyl-3-phenylprop-2-en-1-amine, is added 20.5 g p-cresol and 15.8 g methanesulfonic acid and heated to 130° C. for 6 hours. Chromatography shows disappearance of the peak corresponding N,N-diisopropyl-3-phenylprop-2-en-1-amine, and a fine peak at the retention time of 3-(2-hydroxy-5-methylphenyl)-N,N-diisopropyl-3-phenylpropylamine. From the reaction mixture the (+)-(R)-3-(2-hydroxy-5-methylphenyl)-N,N-diisopropyl-3-phenylpropylamine is isolated as follows: Water and toluene (200 ml each) are added to the reaction mixture and pH adjusted to 9.5. The toluene layer is isolated and washed with water. Distilling off the toluene leaves an oily mass. This is taken up in 300 ml 2-propanol, added 0.55 eq tartaric acid and 0.55 eq formic acid, After stirring overnight, the suspension is filtered. The wet filter cake is approximately 97% pure. The wet filter cake is taken up in 300 ml 2-propanol and heated to reflux, cooled to 5° C., filtered and dried (yield 85%). Purity on HPLC (achiral) 99.5%.

Provenance & Evidence