**4.5 Synthesis of 1,4-bromobenzyl, 4-phenyl-1H-1,2,3-triazole**

1-Bromo-4-(bromomethyl) benzene 0.249 g (1.0 mmol), sodium azide 0.091 g (1.4 mmol) and phenyl acetelyne 0.112 g (1.1 mmol) were suspended in polyethylene glycol-400 (5 mL). To this reaction mixture in copper iodide (10 mol%) was added and the reaction mixture was stirred for 20 min at 25°C. After completion of the reaction (monitored by TLC), the product was extracted with EtOAc and the organic extract was dried. The crude product was recrystallized from ethanol to yield the desired product.

Yield: 82%, MF/FWt: C15H12BrN3/313.02, MP: 140–142°C.

IR (cm<sup>−</sup><sup>1</sup> ): 2980, 1601, 1545, 1225, 1157.

1 H NMR (300 MHz, CDCl3, δ ppm): 8.13–8.15 (d,2H), 7.08–7.10 (d,2H),

 7.80–7.82 (d,2H), 6.85–6.87 (d,2H),7.81–7.83 (t,1H), 8.39 (s,1H, triazole), 4.73 (s,2H). 13C NMR (300 MHz, CDCl3, δ ppm): 53, 113, 114, 118, 133 (carbon triazole), 159, 148, 149, 141.
