Dichloroacetic acid (0.065 mL, 0.78 mmol) was added to a mixture of compound 6 (192 mg, 0.39 mmol), benzyltriethyl ammonium bromide (318 mg, 1.17 mmol) and sodium nitrite (538 mg, 7.8 mmol) in dibromomethane (10 mL). The mixture was stirred at room temperature for 18 hours in the dark. The reaction mixture was then concentrated and the resulting residue was purified by prep. TLC (95% dichloromethane/5% methanol) to afford 88 mg, 42% yield of 4-(2-(5-bromo-4-(2-chloro-4-cyclopropyl-6-methylphenyl)-4H-1,2,4-triazol-3-ylthio)acetamido)-3-chlorobenzoic acid (7).
