By reacting dialkyl 1-oxo-or 2-oxoalkylphosphonates with benzhydrylamine followed by reduction with triacetoxyborohydride and acid hydrolysis gave corresponding aminoalkylphosphonic acids with satisfactory yields. The use of benzylamine, α- methylbenzylamine and tritylamine was unsuccessful in the case of dialkyl 1- oxoalkylphosphonates whereas conversion of 2-oxoalkylphosphonates was also ...