Patent ID: 7053244

Claim:
A process for the preparation of tetrasubstituted ureas comprising: reacting, in a reaction apparatus, at least one corresponding amine with phosgene in the presence of an aqueous inorganic base at a temperature in the range of from 0° C. to 150° C., said process further comprising: feeding the at least one corresponding amine, the phosgene and the aqueous inorganic base on average continuously to the reaction apparatus, forming a two-phase system in the reaction apparatus through the choice of: (i) the tetrasubstituted ureas to be prepared; (ii) the mixing ratios of the substances and substance mixtures to be fed in; (iii) the temperature during the reaction; and, optionally (iv) the feed of an organic solvent which is not completely miscible with water; and discharging the reaction mixture on average continuously from the reaction apparatus.