Sodium hydride → HCID 23023146, compound

Participants

Reaction Steps

Sodium hydride (60% dispersion in oil, 520 mg, 13 mmol) was added portionwise to a suspension of ethyl 5-amino-1-benzylpyrazole-4-carboxylate (2.2 g, 9 mmol) in anhydrous THP (30 ml) at 0° C. The mixture was allowed to warm to room temperature and stirred for 2 h then 1-fluoro-2-nitrobenzene (1.26 g, 9 mmol) was added and the resultant deep purple suspension was stirred at room temperature for 18 h. 1 M KHSO4 was added to quench the reaction and the solvent was removed in vacuo. The residue was dissolved in ethyl acetate and the solution was washed with 0.3 M KHSO4, sat. NaHCO3 and brine, dried over Na2SO4 and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (eluant 75% pet. ether/25% ethyl acetate) to yield ethyl 1-benzyl-5-(2′-nitrophenylamino)pyrazole-4-carboxylate (2.5 g, 76%).

Provenance & Evidence