A novel facile one-pot synthesis of the 1,2-azaphospholanes by intramolecular alkylation of 3-halopropyl amides of tricoordinate phosphorus has been suggested. Using this method, a series of the differently N-substituted 1,2-azaphospholanium salts were synthesized. 3-Aminopropylphosphine oxides were obtained by hydrolysis of the salts. A probable mechanism of the 1,2-azaphospholanium salts formation is discussed. (C) 2003 Wiley Periodicals, Inc.