Urea → Cyanuric acid

Participants

Reaction Steps

300 g of urea prills and 495 g of N-methylpyrrolidone were charged into a 1-liter glass reactor fitted with stirrer, condenser and thermometer. The reaction mixture was heated with a mantle and maintained at reflux for a 2-hour period during which the reaction temperature increased from 185° to 212° C. On cooling, the reaction mixture solidified at about 35° C. The reaction mixture was reheated to about 160° C. to make it stirrable, cooled to 40°-50° C. and filtered. The cake set up in the filter funnel and had to be broken up. On washing with water, the filter cake solidified again into a hard cement-like solid with release of some heat. The solid was broken up, washed further, and dried giving 129 g (60% yield) of impure cyanuric acid containing 5.6% ammelide and 0.4% ammeline.

Provenance & Evidence