Oxalic Acid → 5-[1,1-Diphenyl-3-(4-phenylpiperidino)propyl]-2-methyl-1,3,4-oxadiazole oxalate

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Reaction Steps

2.0 Parts of 5-[1,1-diphenyl-3-(4-phenylpiperidino)propyl]-1H-tetrazole hemimethanolate, 6.21 parts of acetic anhydride and 20 parts by volume of pyridine are heated together to reflux for 1 hour and 20 minutes. The mixture is then cooled and stripped in vacuum. The resulting residue is taken up in ether. The ether solution is washed with sodium hydroxide, dried over sodium sulfate and then stripped in vacuum to give a gum. 1.74 Parts of this gum dissolved in 6 parts by volume of methanol and 0.35 part of oxalic acid dissolved in 4 parts by volume of methanol are mixed together. This solution is diluted with ether to just below the point of cloudiness. The crystals which form are filtered off and dried in vacuum to provide 5-[1,1-diphenyl-3-(4-phenylpiperidino)propyl]-2-methyl-1,3,4-oxadiazole oxalate, melting at 180° - 190° C., having the following formula ##STR9##

Provenance & Evidence