Synthesis and structural identification of 5-amino-4-hydroxyiminopyrazoles and(E)-N1-aryl-3-aryl-4-[(substituted pyrazolyl)diazenyl] pyrazoles from 5-aminopyrazoles with ethyl nitrite or sodium nitrite

摘要

5-Amino-4-hydroxyiminopyrazoles and(E)-N1-aryl-3-aryl-4-[(substitutedpyrazolyl)diazenyl]pyrazoles derivatives were conveniently synthesized as the corresponding products by reacting 5-aminopyrazoles with ethyl nitrite or sodium nitrite in w10% aqueous HCl solution. All of 5-amino-4-hydroxyiminopyrazoles and diazenes were fully identified by spectroscopic methods. Based on the single-crystal X-ray diffraction study, 5-amino-4-hydroxyiminopyrazole structure first identified and presented in this work as opposed to a nitroso tautomer.