Acetic Acid → HCID 19839443, compound

Participants

Reaction Steps

3 g of 3-amino-4-bromo-1-(2-pyridyl)pyrazole was suspended in 60 ml of hydrochloric acid, to which 2.5 ml of an aqueous solution containing 1.2 g of sodium nitrite was added dropwise at -10° to -5° C. to prepare a solution of diazonium salt. This solution of diazonium salt was added dropwise at 5° C. to 30 ml of acetic acid saturated with sulfur dioxide containing 0.5 g of cuprous chloride. After stirring at room temperature for 20 minutes, 100 ml of water and 300 ml of 1,2-dichloroethane were added and stirred to separate an organic layer. To the organic layer, added was 10 ml of 28% ammonia water, followed by vigorous stirring at room temperature for 1 hour. Thereafter, solvent was evaporated under reduced pressure and 200 ml of ethyl acetate was added. After further stirring, insolubles were filtered off and ethyl acetate was evaporated to obtain 2.2 g of the title compound as a crude product. This crude product was purified by a silica gel column chromatography (developed with ethyl acetate) to obtain 0.5 g of the title compound as a pure product. m.p.: 201° to 203° C.

Provenance & Evidence