Synthesis of Potential Bioactive Novel 7‐[2‐Hydroxy‐3‐(1,2,3‐triazol‐1‐yl)propyloxy]‐3‐alkyl‐4‐methylcoumarins

A series of 50 novel 7-[2-hydroxy-3-(1,2,3-triazol-1-yl)propyloxy]-3-alkyl-4-methylcoumarins had been designed and synthesized in good to excellent yields via Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction “click chemistry” of 7-(3-azido-2-hydroxypropyloxy)-3-alkyl-4-methylcoumarins with variety of acetylene derivatives. In turn, the precursor compound, that is, 7-(3-azido-2-hydroxypropyloxy)-3-alkyl-4-methylcoumarin, was synthesized by condensation of epichlorohydrin with 7-hydroxy-3-alkyl-4-methylcoumarins followed by opening of the epoxide ring in the resulted 7-epoxymethoxy-3-alkyl-4-methylcoumarins with sodium azide. All the synthesized compounds were unambiguously identified on the basis of their spectral data analyses (IR, 1H-NMR, 13C-NMR spectra, and HRMS).