2-(Ethoxymethylene)propanedinitrile → 5-amino-1-(2,3-dichlorophenyl)-1H-pyrazole-4-carbonitrile

Participants

Reaction Steps

(2,3-Dichlorophenyl)hydrazine hydrochloride (CAS no. 21938-47-6) (6.06 g, 28.4 mmol) was partitioned between EtOAc and 2M NaOH. Separated. The organic solution was dried (MgSO4), filtered and reduced to give the free base. 2-(Ethoxymethylene)malononitrile (3.47 g, 28.39 mmol) was added portionwise to a stirred solution of (2,3-dichlorophenyl)hydrazine in MeOH (50 mL), under nitrogen at 5° C. The resulting solution was allowed to stir for a further 1 hour. The reaction mixture was then heated to reflux and was stirred for 3 hours. The reaction mixture was allowed to cool to ambient temperature, then was evaporated to afford the product (7.19 g, 100%) which was used without further purification. 1H NMR (400 MHz, DMSO) δ 6.75 (2H, s), 7.48-7.53 (2H, m), 7.77 (1H, s), 7.79-7.84 (1H, m).

Provenance & Evidence