Reaction of benzolactams with triethyl phosphite prompted by phosphoryl chloride affords benzoannulated monophosphonates instead of expected bisphoshonates
gave cyclic aminomethylene-gem-bisphosphonates in reaction with triethyl phosphite and phosphoryl chloride, the corresponding benzoannulated lactams usually provide monophosphonates of variable structures, which depend on size of the substrate aliphatic ring. Most likely they are obtained by dephosphonylation of bisphosphonates, which form as initial products of this reaction. These phosphonate esters