Acetic Acid → HCID 22157904, compound

Participants

Reaction Steps

Ethyl acetoacetate (8.5 g) and acetic acid (75 ml) were added to 3-(4-methoxyphenylamino)-1-phenyl-2-pyrazolin-5-one (14 g) and refluxed while heating for 6 hours. The reaction solution was poured into 150 ml of water, and the resulting solid was dissolved in a mixture of methanol (500 ml) and acetone (150 ml) while heating. The solution was cooled to obtain 8.4 g of 7-(4-methoxyphenyl)-4-methyl-2-phenylpyrazolo(3,4-b)pyridine-3,6-dione (melting point 189°-190° C.). In a solution prepared by adding methanol (40 ml) and triethylamine (2.8 ml) to these crystals (3.47 g) was dissolved, 1,7-diphenyl-1,7-diaza-1,3,5-heptatriene hydrochloride (2.85 g), and then acetic anhydride (1.88 ml) was added thereto, and stirred at room temperature for one hour. The resulting precipitate was collected by filtration, washed with methanol and dried to obtain 5-[5-(N-acetylanilino)-2,3-pentadienylidene]-7-(4-methoxyphenyl)-4-methyl-2-phenylpyrazolo(3,4-b)pyridine-3,6 -dione (4.1 g). N,N-dimethylformamide (40 ml), 7-(4-methoxyphenyl)-4-methyl-1-phenyl- 2-pyrazolin-5-one (2.4 g) and triethylamine (0.98 ml) were added to these crystals (3.8 g), and stirred at 50° C. for 2 hours. After filtration of the reaction solution, 10-fold volume of ethyl acetate was added for crystallization. The crystals were recrystallized from acetonitrile to obtain compound II-3 (1.0 g). Melting point 260° C. (decomposed).

Provenance & Evidence