Step 3: Synthesis of 2-(4-bromophenyl)-2H-1,2,3-triazole [1.1.5c]. 1.1.5b (68 mg, 0.468 mmol) was dissolved in concentrated sulfuric acid (2 mL), and bromine (0.024 mL, 0.468 mmol) was slowly added, followed by silver sulfate (175 mg, 0.56 mmol). The reaction mixture was stirred at room temperature for 40 minutes. After completion of the reaction, the mixture was poured into water and extracted with ethyl acetate. The organic layer was dried with anhydrous sodium sulfate and concentrated under reduced pressure to give 1.1.5c (40 mg, 38% yield) as an off-white solid.LCMS (m/z): 225.9 [M + H]+.1H NMR (400 MHz, CDCl3) δ: 7.99 (d, J = 8.61 Hz, 2H), 7.83 (s, 2H), 7.62 (d, J = 8.61 Hz, 2H).
![2-(4-Bromo-Phenyl)-2H-[1,2,3]Triazole](/CAS/20180703/GIF/74733-90-7.gif)