1,2-Dibromoethane → 1-(1-(2-Bromoethyl)-3-(2,5-dimethyl-1H-pyrrol-1-yl)-1H-pyrazol-5-yl)ethanone

Participants

Reaction Steps

A 250-mL round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 150d (5.4 g, 1.0 eq., 26.6 mmol), 1,2-dibromoethane (20.0 g, 4.0 eq., 106.4 mmol), K2CO3 (7.34 g, 2.0 eq., 53.2 mmol), and acetonitrile (100 mL). The reaction mixture was reflux for 5 hrs. It was cooled to room temperature and filtered. The filtrate was concentrated under reduced pressure. The residue was purified by silica-gel column chromatography eluting with 6:1 petroleum ether/ethyl acetate to afford 150e (7.5 g, 91%) as a colorless oil. MS-ESI: [M+H]+ 309.9

Provenance & Evidence