Synthesis of organotin bis(pyrazol-1-yl)methane-tetracarboxylates and tris(pyrazol-1-yl)methane-hexacarboxylates

Bis(pyrazol-1-yl)methane-tetracarboxylic acid and tris(pyrazol-1-yl)methane-hexacarboxylic acid, namely bis(3,5-dicarboxypyrazol-1-yl)methane (CH2[3,5-Pz(CO2H)2]2) and tris(3,5-dicarboxypyrazol-1-yl)methane (CH[3,5-Pz(CO2H)2]3), have been synthesized by the oxidation reaction of bis(3,5-dimethylpyrazol-1-yl)methane and tris(3,5-dimethylpyrazol-1-yl)methane with an excess of KMnO4. Reaction of CH2[3,5-Pz(CO2H)2]2 with (R3Sn)2O yielded the...