Azetidine has been prepared and its nucleophilicity towards bromoaromatic compounds has been investigated. In this way the synthesis of a number of new N-arylazetidines has been accomplished. The infra red spectra of these azetidines, together with those of a few N-alkylazetidines, prepared from the corresponding 3-aminopropanols, have been compared. Cleavage of the 4-membered ring in N-substituted azetidines, using hydrogen bromide, has been briefly examined.