Nitrogen → 1-(2,4-Dichlorobenzyl)-6-trifluoromethyl-1H-indazole-3-carboxylic Acid methyl ester

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Reaction Steps

6-Trifluoromethyl-1H-indazole-3-carboxylic acid methyl ester (2.75 g, 0.0112 mol) was dissolved in acetonitrile (50 mL), and potassium carbonate (10 g, 0.07 mol), 2,4-dichlorobenzyl chloride (2.42 g, 0.01239 mol) and tetrabutylammonium iodide (catalytic) were added. The reaction mixture was heated to reflux and refluxed for 2 h under good stirring. The progress of the reaction was monitored by TLC. After completion of the reaction, potassium carbonate was filtered while hot and then washed with acetone. The combined solvents were distilled off under reduced pressure to afford the crude mixture of N1 and N2 benzylated products. The isomers were separated by column chromatography (silica gel, eluent started with hexane then changed to 8:2 hexane, ethyl acetate).

Provenance & Evidence