Benzaldehyde, acetone, and N Boc piperidone phenylhydrazones, as well as azines de rived from aromatic aldehydes and ketones, react with diethyl phosphite in the presence of [tetra(tert butyl)phthalocyanine]aluminum chloride to give α hydrazino phosphonates in high yields.A search for new routes to α hydrazino phosphonates, which are biologically active compounds 1-4 and structur al analogs of the corresponding α amino phosphonic ac ids, still attracts the attention of researchers. Known meth ods for the synthesis of these compounds include (1) se lective reduction of α hydrazono phosphonic acids with NaBH 3 CN or BH 3 •THF, 5 (2) nucleophilic substitution in 3 methoxy 1,2,3,4 pyridazines using dimethyl phos phite in the presence of Lewis acids, 6 nucleophilic sub stitution in modified α hydroxy phosphonates, 7 (3) a MeONa catalyzed reaction of 2 nitrobenzaldehyde phenylhydrazone with dimethyl phosphite, 8 and (4) reac tions of N,N dimethylhydrazine with aldehydes and sily lated phosphite in the presence of LiClO 4 (see Refs 9, 10).Preparation of α hydrazino phosphonates is based on (1) base catalyzed reactions of aliphatic aldazines with dialkyl phosphites followed by hydrolysis (note that this method is unsuitable with aromatic aldazines) 10-12 and (2) noncatalytic addition of dialkyl phosphites to benzal dehyde azine and cyclohexanone azine. 13-17Thus, a quest for an efficient general route to α hydr azino phosphonates from both aromatic aldehydes and ketones remains of current interest.Previously, we have proposed a catalytic three com ponent "one pot" synthesis of α amino phosphonates (the Kabachnik-Fields reaction) with [tetra(tert butyl)phtha locyanine]aluminum chloride ( t PcAlCl) as a catalyst. 18, 19 We attempted to obtain α hydrazino phosphonates in a similar way using hydrazine derivatives as the amine component. However, the three component "one pot" syn thesis in conventional solvents such as dichloromethane, alcohols, toluene, etc. failed because of rapid formation of insoluble hydrazones and azines. That is why we further used separately prepared hydrazones and azines in the hy drophosphorylation reaction (a version of the Pudovik re action 20 ). Recently, 21 we have published our data on the phosphorylation of some N acetylhydrazones and N Boc hydrazones in the presence of t PcAlCl. In the present work, we studied methyl and arylhydrazones and azines.We found that both the t PcAlCl catalyzed and non catalytic hydrophosphorylation of acetone phenylhydr azone occurs in an excess of diethyl phosphite (DEP) serv ing as a solvent as well. However, the presence of the catalyst increases the yield of α hydrazino phosphonate 1 from 45 to 70%, the other conditions being the same (80 °C, 8 h) (Table 1, entries 1, 2). N Boc Piperidone phenylhydrazone also reacts with DEP in the presence of t PcAlCl to give the corresponding α hydrazino phospho nate 2 in 68% yield (entry 3).A t PcAlCl catalyzed reaction of benzaldehyde phenyl hydrazone with an excess of DEP at 80 °C for 50 h affords α hydrazino phosphonate 3...