Citric Acid → HCID 86746365, compound

Participants

Reaction Steps

3-(3-Amino-1,4-dihydro-1-phenyl-[1]-benzothiopyrano[4,3-c]pyrazol-3-yl)-2-cyano-3-oxo-N-phenyl-propanamide (1.2 g) dissolved in anhydrous dimethylformamide (70 ml) containing pyridine (1 ml) is reacted with ethyl oxalyl chloride (0.7 g) under stirring at room temperature for 6 hours. The reaction mixture is diluted with ice water and acidified to pH 4 with citric acid. The precipitate is filtered and washed with water. Crystallization from CHCl3 /ethanol yields 1.2 g of 2-cyano-3-(8-ethoxalylamino-1,4-dihydro-1-phenyl-[1]-benzothiopyrano[4,3-c]pyrazol-3-yl)-3-oxo-N-phenyl-propanamide, m.p. 273°-277° C.

Provenance & Evidence