Ethanol → Ethyl 5-amino-3-(2-hydroxyethoxy)-1H-pyrazole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-[(cyano)(ethoxycarbonyl)vinyl]-1,3-dioxolane (2.0 g) in ethanol (20 mL) were added hydrazine hydrochloride (748 mg) and sodium acetate (1.34 g), and the mixture was stirred at 80° C. (external temperature) for 1 hour. After cooling to room temperature, the reaction mixture was filtered through Celite, and the filtrate was concentrated in vacuo. The resultant crude product was purified by column chromatography on silica gel (solvent: chloroform/methanol=100/0 to 85/15) to give 3-amino-4-ethoxycarbonyl-5-[2-(hydroxy)ethoxy]-1H-pyrazole (2.01 g, yield: 86%) as a pale pink solid.

Provenance & Evidence