The reaction of N-(2-chloroethyl)-2-azabicyclo[2.2.2]octane (I) with diphenylacetonitrile (II) by means of KOH in refluxing methyl ethyl ketone gives 4-[2-azabicyclo[2.2.2]octan-2-yl]-2,2-diphenylbutyronitrile (III), which by reaction with NaN3 in DMF at 125 C is converted into 5-[1,1-diphenyl-3-(2-azabicyclo[2.2.2]octan-2-yl)propyl]-1H-tetrazole (IV). Finally, this compound is treated with refluxing acetic anhydride.