Methanol → Isopropyl 5-(2-aminoethoxymethyl)-3-cyano-7-(2,3-difluorophenyl)-4,7-dihydropyrazolo[1,5-a]pyrimidine-6-carboxylate hydrochloride

Participants

Reaction Conditions

Reaction Steps

To a solution of 1.3 g of isopropyl 3-cyano-7-(2,3-difluorophenyl)-5-[2-(phthalimido)ethoxymethyl]-4,7-dihydropyrazolo[1,5-a]pyrimidine-6-carboxylate in a mixed solvent of 12 ml of methanol and 12 ml of chloroform is added 142 μl of hydrazine hydrate and the mixture is refluxed at 50° C. for 5 hours. After the solvent is distilled off, to the residue is added aqueous sodium hydrogencarbonate and then extracted with ethyl acetate. The organic layer is washed with water, dried over sodium sulfate and ethanolic hydrochloric acid is added to convert into hydrochloride. The obtained crystals are recrystallized from methanol to give 0.4 g of isopropyl 5-(2-aminoethoxymethyl)-3-cyano-7-(2,3-difluorophenyl)-4,7-dihydropyrazolo[1,5-a]pyrimidine-6-carboxylate hydrochloride 1/4 hydrate.

Provenance & Evidence