Pyrazole → HCID 72343819, compound

Participants

Reaction Steps

4-Hydrazinopyridine hydrochloride (366 mg, 2.51 mmol) and methyl 4-(5-bromothiophen-2-yl)-2,4-dioxobutanoate (724 mg, 2.5 mmol) were suspended in MeOH (12 mL) and heated to reflux to afford a yellow solution. After refluxing for 24 hours the reaction was allowed to cool to ambient temperature and was concentrated under reduced pressure to afford an orange oil. LC/MS analysis showed it to be a mixture of two isomers of the hydrazone with a small amount of cyclized pyrazole present. This material was carried on the dehydrative cyclization to prepare the cyclized pyrazole. MS(ES): 384 [M+H]+.

Provenance & Evidence