Four-component reaction of cyclobutanone, dibenzylamine and (Nisocyanimino)
triphenylphosphorane in the presence of aromatic carboxylic acids proceed
smoothly at room temperature and under neutral conditions to afford
N,N-dibenzyl-N-{1-[5-(3-aryl)-1,3,4-oxadiazol-2-yl]cyclobutyl}amine
derivatives in high yields.