Cesium carbonate → Tert-butyl 2-[(4-{[4-(dimethylamino)phenyl]ethynyl}phenyl)acetyl]hydrazinecarboxylate

Participants

Reaction Steps

To a mixture of 4-bromo-N,N-dimethylaniline (175 mg, 0.88 mmol), cesium carbonate (476 mg, 1.46 mmol), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (22 mg, 0.04 mmol) and bis(acetonitrile)dichloropalladium (II) (10 mg, 0.04 mmol) was added anhydrous acetonitrile (2 ml), and the mixture was stirred at room temperature for 15 mins. A solution of tert-butyl 2-[(4-ethynylphenyl)acetyl]hydrazinecarboxylate (200 mg, 0.73 mmol) in anhydrous acetonitrile (4 ml) was added, and the mixture was stirred at 80° C. for 5 hrs. After cooling, the reaction mixture was filtered, and the insoluble material was washed with ethyl acetate. The filtrate and washing solution were combined and concentrated under reduced pressure. The concentrated residue was purified by silica gel column chromatography (chloroform:methanol=97:3) to give tert-butyl 2-[(4-{[4-(dimethylamino)phenyl]ethynyl}phenyl)acetyl]hydrazinecarboxylate (110 mg, yield 38%) as a yellow solid.

Provenance & Evidence