Ethyl 4-piperidinecarboxylate → Ethyl 1-{[4-(2-methyl-1,2,3,4-tetraazol-5-yl)phenyl]methyl}piperidine-4-carboxylate

Participants

Reaction Steps

A solution of 30.0 grams (0.191 mole) of ethyl isonipecotate in 75 mL of DMSO and 99 mL of methanol was stirred and 61.7 grams (0.477 mole) of N,N-diisopropylethylamine, followed by 40.2 grams (0.159 mole) of 5-[4-(bromomethyl)phenyl]-2-methyl-1,2,3,4-tetraazole (known compound-U.S. Pat. No. 5,639,763) were added. Upon completion of addition the reaction mixture was stirred at ambient temperature for about 72 hours. The reaction mixture was then diluted with 175 mL of ethyl acetate and washed with 175 mL of a solution comprised of one part of an aqueous solution saturated with sodium chloride and one part of water. The organic layer was concentrated under reduced pressure to a residue. NMR analysis of the residue indicated the presence of some of the starting ethyl isonipecotate. The residue was dissolved in 370 mL of methanol and water was added to precipitate a solid material. After standing for about 20 minutes, the solid was collected by filtration and was washed with a cold solution of one part methanol and one part of water. The solid was dried, yielding 32.9 grams of the subject compound. A second crop of solid was collected from the filtrate, yielding an additional 11.0 grams of the subject compound. The NMR spectra were consistent with the proposed structure.

Provenance & Evidence