Palladium (II) acetate (2.5 mg, 0.011 mmol) and triphenylphosphine (11 mg, 0.044 mmol) were added to diisopropylamine (4 ml), and the mixture was stirred at room temperature for 20 mins. N-(4-Bromophenyl)acetamide (78 mg, 0.365 mmol) and tert-butyl 2-[(4-ethynylphenyl)acetyl]hydrazinecarboxylate (100 mg, 0.365 mmol) were added, and the mixture was stirred at 70° C. for 2 hrs. Anhydrous acetonitrile (2 ml) was added, and the mixture was further stirred at 70° C. for 1 hr. The reaction mixture was cooled and concentrated. The residue was purified by silica gel column chromatography (dichloromethane:methanol=97:3) to give tert-butyl 2-({4-[(4-acetamidophenyl)ethynyl]phenyl}acetyl)hydrazinecarboxylate (30 mg, yield 20%).
