“…Due to the importance and application of 1,2,3-triazoles bearing the benzothiazole group [ 27 , 28 ], the synthesis of these derivatives is essential for organic chemists and biologists, and efforts are underway to design drugs based on these compounds with high activity and lower toxicity. As a result of our group’s experience synthesizing 1,4-disubstituted 1,2,3-triazole derivatives [ 29 , 30 , 31 , 32 , 33 , 34 ], the new 1,2,3-triazoles were prepared using benzothiazole groups 5a – f via a 1,3-dipolar cycloaddition of S -propargylated mercaptobenzothiazole 3 , sodium azide, and α-halo ester/amide 4 in the presence of CuSO 4 /sodium ascorbate in a mixture of H 2 O/ t -BuOH ( Scheme 1 ). The density functional theory (DFT) calculations, with the B3LYP/6-31 + G(d, p ) method, were applied to investigate the physicochemical properties of the characterized structure of 5e , including structural, electronic, and spectral analysis.…”