Ammonium Acetate → 6-(3,4-dimethoxyphenyl)pyrazolo[1,5-a]pyrazin-4(5H)-one

Participants

Reaction Conditions

Reaction Steps

Ammonium acetate (4.16 g, 54.0 mmol) was added to a solution of ethyl 1-(2-(3,4-dimethoxyphenyl)-2-oxoethyl)-1H-pyrazole-5-carboxylate 5.01 (195 mg, 0.61 mmol) in Acetic Acid (5.4 mL) at room temperature. Mixture was heated at 110° C. overnight. An additional 900 mg of ammonium acetate was added and mixture was heated at 110° C. for 3.5 hours, and then cooled to room temperature. Acetic acid was concentrated and residue was taken up in ethyl acetate and washed with 1:1 water/saturated NaHCO3 (aq). Layers were separated and aqueous was extracted with ethyl acetate. Combined organic layers were washed with 1:1 brine/saturated NaHCO3 (aq), dried (Na2SO4), filtered, and concentrated under reduced pressure to yield 6-(3,4-dimethoxyphenyl)pyrazolo[1,5-a]pyrazin-4(5H)-one 5.02, which was used without further purification.

Provenance & Evidence