Water → N-(5-Hydroxy-2-oxo-1,2,3,4-tetrahydroquinolin-8-yl)urea

Participants

Reaction Conditions

Reaction Steps

10.7 g of 8-amino-5-hydroxy-3,4-dihydrocarbostyril hydrochloride was dissolved in 300 ml of water, and a solution of 4.06 g of potassium cyanide dissolved in 100 ml of water was added thereto while stirring at a temperature of 50° C. After stirring the mixture for one hour at 50° C., the precipitated crystals were recovered by filtration, washed successively with 1 l of water and methanol to obtain 8.75 g of 5-hydroxy-8-ureido-3,4-dihydrocarbostyril as colorless amorphous crystals having a melting point of 209.0°-211.2° C.

Provenance & Evidence