| abstract |
A new and improved process for making phenylisopropylurea derivatives having the formula:n nwherein R' is selected from hydrogen, halogen, alkyl, alkenyl, haloalkyl or R 2 groups and R 2 is selected from phenyl, alkyl-substituted phenyl alkoxy-substituted phenyl or haloalkyl-substituted phenyl is disclosed. The process comprises reacting a substituted urea of the formula:n nwith an alkenyl aromatic compound of the formula:n nin a polar aprotic solvent, in the presence of an acid catalyst, preferably, sulfuric acid, substituted sulfonic acids or Lewis acids, and stirring the reaction mixture at a temperature of about 20 to 80°C until formation of the precipitated phenylisopropylurea derivative is substantially complete. |