Hydrochloric Acid → HCID 18962905, compound

Participants

Reaction Steps

3-(1,4-dihydro-1-phenyl-[1]-benzopyrano[4,3-c]pyrazol-3-yl)-3-oxo-propanenitrile (2.1 g) is reacted with phenyl isocyanate (0.8 g) in the presence of triethylamine (0.75 g) in dimethylformamide (20 ml) under stirring at 25°-30° C. for 90 minutes. The reaction mixture is diluted with ice water, acidified to pH 2 with HCl and the precipitate is filtered and washed with water. Crystallization from dichloromethane/methanol gives 2.5 g of 2-cyano-3-(1,4-dihydro-1-phenyl-[1]-benzopyrano[4,3-c]pyrazol-3-yl)-3-oxo-N-phenyl-propanamide, m.p. 280°-282° C., NMR (CDCl3) δppm: 5.54 (s) (2H, --CH2O--), 6.7-7.7 (m) (14H, phenyl protons), 8.94 (s) (1H, CONH--), 16.4 (bs) (1H, enol).

Provenance & Evidence