Phenylacetyl chloride → 3-Benzyl-7-(4-bromo-2-chlorophenylamino)-8-chloro-[1,2,4]triazolo[4,3-a]pyridine-6-carboxylic acid methyl ester

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Reaction Steps

Phenylacetyl chloride (152 μL, 1.148 mmol) was added to a solution of 4-(4-bromo-2-chlorophenylamino)-5-chloro-6-hydrazinonicotinic acid methyl ester (49) (0.233 g, 0.574 mmol) and triethylamine (160 μL, 1.148 mmol) in CH2Cl2 (5.7 mL) at 0° C. After warming to room temperature, an additional 75 μL phenylacetyl chloride was added. After 6 hours, the reaction mixture was concentrated and diluted with EtOAc. The organic layer was washed with water and brine, dried (Na2SO4) and concentrated. The residue (50b) was diluted with dichloroethylene (2 mL) and POCl3 (465 μL, 5.082 mmol) was added. After stirring at reflux for 12 hours, the reaction mixture was cooled to room temperature and concentrated. The residue was diluted with EtOAc and saturated NaHCO3 was added and the mixture stirred for 20 minutes. The resulting solid was collected by filtrate to give the desired product (51b) (97 mg, 30%).

Provenance & Evidence