Sodium nitrite (2.76 g, 40 mmol) was added to a solution of methyl 2-(5-amino-4-(1-cyclopropylnaphthalen-4-yl)-4H-1,2,4-triazol-3-ylthio)acetate (0.71 g, 2 mmol) and benzyltriethylammonium chloride (1.63 g, 6 mmol) in bromoform (10 mL). Dichloroacetic acid (0.33 mL, 4 mmol) was then added and the reaction mixture stirred at room temperature for 3 h. The mixture was directly loaded onto a 7-inch column of silica gel, packed with dichloromethane (DCM). The column was first eluted with DCM until all bromoform eluted, then eluted with acetone/DCM (5:95) to give methyl 2-(5-bromo-4-(1-cyclopropylnaphthalen-4-yl)-4H-1,2,4-triazol-3-ylthio)acetate (713 mg, 85%).
