Methyl iodide → 1-Tert-butyl-4-chloropiperidine

Participants

Reaction Steps

The imine bond can be activated by quaternization to allow the nucleophilic addition of Grignard reagent. Methyl iodide was added to 1-methyl-3,4-dihydroisoquinoline, generating the iminium salt 1,2-dimethyl-3,4-dihydroisoquinolinium iodide.20 This iminium salt is more reactive than the imine. Methylmagnesium chloride reacted with the iminium, generating 1,1,2-trimethyl-1,2,3,4-tetrahydroisoquinoline. The reaction of methylmagnesium chloride with the iminium salt N-isopropylidene-4-chloropiperidinium chloride gave 1-tert-butyl-4-chloropiperidine.21

Provenance & Evidence