Synthesis and characterization of 3(5)-substituted 1H-pyrazole carboxylic acid and copper complex

Four kinds of 3(5)-substituted 1H-pyrazole carboxylic acid were designed and synthesized with four deferent kinds of acetones and diethyl oxalate as the raw materials and all the title compounds were characterized by IR and 1H NMR spectra.Compound 3a was further used to coordinate with metal ion(Cu2+) and a binuclear copper complex was obtained in the triclinic space group of P-1 with cell dimension of a=7.082(8),b=9.156(10),c=25.86(3),α=97.088(19) °,β=92.024(18) °,γ=112.649(13)°,V=1529(3)3,Z=4,Dc=1.597g/cm3,as a result of which,the molecular structure of pyrazole was confirmed.