Water → HCID 12318784, compound

Participants

Reaction Conditions

Reaction Steps

42.5 g of 4-chloroanthranilic acid were dissolved in 250 ml of N-methylpyrrolidone and 29.5 g of phenyl isocyanate were added dropwise at room temperature in 30 minutes. The mixture was further stirred for 5 hours at 80° C. and then 24.5 g of concentrated sulphuric acid were added dropwise in the course of 1 hour. The mixture was then further stirred at 80° C. for 3 hours, then cooled to room temperature, 500 ml of water were added, the product precipitated out was filtered off by suction, washed with water and dried in a vacuum drying cabinet. In this manner 57.4 g (85% of theory) of pure 3-phenyl-7-chloro-quinazoline-2,4-dione were obtained having a melting point of above 300° C.

Provenance & Evidence