Microwave-Assisted Synthesis, NMR, and Cyclic Voltammetric Study of Some Novel 3,5-Disubstituted 1H-1,2,4-Triazoles Containing Hetaryl Fragments

The synthesis of the title compounds 5a-c has been accomplished by a Suzuki cross coupling reaction between arylbromide 3 and 5-Indole boronic acid to furnished precursor 4, which was used as a key intermediate for the synthesis of the preceding targets. Thus, treatment of 4 with variously-substituted arylsulfonyl chlorides, the sulfonate derivatives 5a-c were obtained in good yields and high purity. The structures of 5a-c were characterized by 1H, 13C NMR, and liquid chromatography-mass spectroscopy techniques. Further, the electrochemical behavior of compound 5c has been investigated by cyclic voltammetry using Britton-Robinson (B-R) buffer at pH 3, pH 7 and pH 9, acetate buffer pH 3, and Phosphate buffer pH 3. A broad anodic cyclic voltammetric wave at Eap= 640 mV was observed.