Aza-15-crown-5 Hydrochloride (I). A stream of dry HCI was passed with stirring and cooling through a solution of 2.2 g of aza-15-crown-5 [4] in absolute ether until the mixture was saturated. The resulting precipitate was removed by filtration, washed with absolute ether, and dried to give 2.4 g (94%) of I with mp 69-70~ PMR spectrum (CDCI3, 6, ppm): 2.75 t, 3.55 t, 7.1 s.