Preparation of chlorphenyldimethyl-ureas

Claim 1

IN A PROCESS FOR THE MANUFACTURE OF A 3(CHLOROPHENYL) -1,1-DIMETHYLUREA IN WHICH THERE ARE 1 TO 3 CHLORINE SUBSTITUENTS ON THE PHENYL RADICAL, ONE CHLORINE SUBSTITUENTS BEING IN THE PARA POSITION TO UREA NITROGEN ATOM TO WHICH THE RADICAL IS LINKED, THE STEPS COMPRISING HEATING AT A TEMPERATURE OF 70* C. TO 105* C. AN AQUEOUS SOLUTION OF UREA AND AN ACID SALT OF A CHLOROANILINE HAVING ONE TO THREE CHLORINE SUBSTITUENTS, ONE CHLORINE BEING IN THE PARA POSITION, AT LEAST TWO MOLS OF UREA BEING USED FOR EACH MOL OF THE CHLOROANILINE SALT, WHEREBY A CHLOROPHENYLUREA FORMS AND PRECIPITATES FROM THE SOLUTION, SEPARATING SAID CHLROPHENYLULREA PRECIPITATE FROM THE REACTION MASS, HEATING THE SEPARATED CHLOROPHENYLUREA IN SOLUTION IN AN INERT SOLVENT WITH AN EXCESS OF DIMETHYLAMINE AT A TEMPERATURE OF 135* C. TO 225* C., WHEREBY THE AFOREMENTIONED CHLOROPHENYL DIMETHYLUREA PRODUCT AND BY-PRODUCT AMMONIA ARE FORMED IN A REACTING MASS, AND REMOVING SAID AMMONIA FROM THE REACTING MASS SUBSTANTIALLY AS FAST AS IT IS FORMED.