Potassium Phosphate, Tribasic → 1h-Indazole,4-bromo-1-(4-methoxyphenyl)-6-methyl-

Participants

Reaction Steps

Crude 2,6-dibromo-4-methylbenzaldehyde[4-(methyloxy)phenyl]hydrazone (Intermediate 14 prepared from 2.62 g of 2,6-dibromo-4-methylbenzaldehyde) was dissolved in toluene (100 mL) and treated with tripotassium phosphate (5 g, 23.55 mmol), tris(dibenzylideneacetone)dipalladium(0) (196 mg, 0.214 mmol) and racemic BINAP (122 mg, 0.196 mmol). The mixture was heated under reflux for 17 hours and then cooled, filtered through celite and evaporated under reduced pressure. The residue was purified by silica gel chromatography using the Flashmaster II (100 g cartridge) eluting with a 100:0 to 0:100 cyclohexane:dichloromethane gradient over 60 minutes to give crude product (801 mg). Further purification by silica gel chromatography using the Flashmaster II (50 g cartridge) eluting with a 100:0 to 75:25 cyclohexane:ethyl acetate gradient over 50 minutes gave the title compound as a colourless solid (499 mg).

Provenance & Evidence