An alpha-hydrazinoalkylphosphonate as building block for novel N-phosphonoalkyl heterocycles

alpha-Hydrazinoalkylphosphonate 3 is a useful building block for the syntheses of novel N-phosphonoalkylheterocycles. N-phosphonoalkylpyrazoles 8 and 9 were prepared by the cyclization reaction of 3 with multifunctioned ethenes 5 and 6 in ethanol under reflux. N-Phosphonoalkyltriazole 10 was synthesized from 3 with N-dimethylthiomethylene benzoyl amide 4 in ethanol under reflux. The structures were confirmed by IR, H-1 NMR, mass spectroscopy, and elemental analysis. At the same time, the preparation of 4 was investigated. (C) 2003 Wiley Periodicals, Inc.