Hydrochloric Acid → HCID 57642348, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 6.7 g (0.032 mole) of ethyl 5-amino-3-methyl-1-(2-propenyl)-1H-pyrazole-4-carboxylate (XV) in 30 mL of concentrated hydrochloric acid was added 8.6 g (0.064 mole) of copper (II) chloride. The mixture was cooled to 0° C. and 2.65 g (0.038 mole) of sodium nitrite was added portionwise over 20 minutes. The mixture was stirred at room temperature for 1 hour, and then at 40° C. for 2 hours. The mixture was diluted with 50 mL of water and extracted twice with chloroform. The chloroform extracts were dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by silica gel chromatography, eluting with ethyl acetate-hexane (1:4) to give 5.0 g of ethyl 5-chloro-3-methyl-1-(2-propenyl)-1H-pyrazole-4-carboxylate (XVI) as a light yellow oil.

Provenance & Evidence