Butanoic acid, 2-[(3-nitrophenyl)methylene]-3-oxo-, 1-methylethyl ester → 1,2,4,7-Tetrahydro-5-methyl-7-(3-nitrophenyl)-2-oxopyrazolo[1,5-a]pyrimdine-6-carboxylic acid, 1-methylethyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-amino-5-pyrazolone (3.57 g; 36.1 mmole) and 2-[(3-nitrophenyl)methylene]-3-oxobutanoic acid, 1-methylethyl ester (10.0 g; 36.1 mmole) in dry dimethylformamide (30 ml) was heated at 70° C. under argon for 24 hours. The reaction mixture was allowed to cool to room temperature and then diluted with ether. The resultant precipitate was filtered off and recrystallized from isopropanol to provide the title compound in crystalline form (4.23 g; melting point 254°-256° C.).

Provenance & Evidence