Short-RInChIKey=SA-FUHFF-UHFFFADPSC-JMPSOWDQCF-UHFFFADPSC-NUHFF-NUHFF-NUHFF-ZZZ

In a vial, 3-azido-1-benzyl-pyrazole (158 mg, 794 μmol, 1.00 equiv) was dissolved in THF (10.00 mL) and water (10.00 mL) (1:1) and copper;sulfate (25.3 mg, 159 μmol, 0.200 equiv), sodium ascorbate (157 mg, 794 μmol, 1.00 equiv) and 1-ethynyl-4-methoxybenzene (136 mg, 134 μL, 1.03 mmol, 1.30 equiv) were added. The reaction mixture was stirred at 50 °C for 16 hours. Then it was diluted with water and extracted three times with methylene chloride. The combined organic phase was washed with water and brine, dried over Na2SO4 and filtered.