2-Chlorophenylhydrazine hydrochloride → HCID 59632248, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of (2-chlorophenyl)hydrazine hydrochloride (1.1 g, 6.1 mmol) and methyl 4-(5-bromopyridin-2-yl)-2,4-dioxobutanoate (1.7 g, 6.0 mmol) in MeOH (30 mL) was divided into two microwave reaction vessels. Each reaction vessel was then heated in the microwave at 120° C. for ten minutes. LC/MS analysis at this time showed the reaction to be essentially complete. The solutions were concentrated under reduced pressure to afford a dark brown semi-solid. This material was taken up in EtOAc and saturated aqueous NaHCO3. The layers were separated and the basic aqueous was extracted with EtOAc (3×). Combined organic extracts were washed with brine, dried over Na2SO4, filtered and concentrated to afford a dark oil. This crude product was purified by flash column chromatography eluting with a gradient from 0% to 100% EtOAc in hexane to afford methyl 5-(5-bromopyridin-2-yl)-1-(2-chlorophenyl)-1H-pyrazole-3-carboxylate (300 mg, 13% yield) as an oil.

Provenance & Evidence