Green microwave versus conventional synthesis, crystal structure of 1-(4-(Benzothiazol-2- yl)piperazin-1-yl)-2-(4-phenyl-1H-1,2,3-triazol-1- yl)ethenone and HS-Analysis

ABSTRACT This study reports an efficient eco-friendly microwave assisted synthesis of 1-(4-(benzothiazol-2- yl)piperazin-1-yl)-2-(4-phenyl-1H-1,2,3-triazol-1-yl)ethanone (4) through the click cyclocondensation of 2-azido-1-(4-(benzo[d]thiazol-2-yl)piperazin-1-yl)ethanone (3) with phenyl acetylene. The synthesis was carried out under optimized copper catalyst copper(II) sulfate pentahydrate/ sodium ascorbate, t-BuOH/water (1:1, v/v) to afford the regioselective 1,4-disubstituted 1,2,3-triazole isomer. The reactions were greatly accelerated using microwave irradiation. The new designed 1,2,3-triazole was fully characterizid by IR, NMR, MS spectral data and X-ray diffraction. The crystal structure of 4 demonstrated a conventional chair conformation for the piperazine ring. Interesting Hirshfeld Surface Analysis (HAS) was conducted showing clear agreement with the XRD analysis.