Trifluoroacetic acid → HCID 19367180, compound

Participants

Reaction Steps

Stage b) Deprotection with trifluoroacetic acid is carried out according to the method of Preparation 2A, Stage b). The product obtained is a mixture of the Z and E isomers. Elution with a 90:10 v/v mixture of methylene chloride and 10% ammoniacal methanol by the Chromatoflash technique on silica furnishes the E isomer in the most polar fractions. The intermediate fractions are chromatographed a second time under the same conditions. All of the fractions with a high E-isomer content are combined, and, as described with regard to Preparation 2B, Stage b), are converted to the hydrochloride, which is recrystallized in isopropanol, then treated in an alkaline medium, extracted with ether and concentrated to furnish (E)-2-(m-chlorocinnamyl)piperidine with a yield of 24%.

Provenance & Evidence