Patent ID: 7999118

Claim:
A process for the N-halogenation of at least one 5-hydrocarbyl hydantoin and/or at least one 5,5-dihydrocarbyl hydantoin, which process comprises concurrently feeding into a reaction zone (i) water, inorganic base, and at least one 5-hydrocarbyl hydantoin and/or at least one 5,5-dihydrocarbyl hydantoin, these being fed separately and/or in any combination(s), (ii) a separate feed of a brominating agent, and (iii) a separate feed of a chlorinating agent, in proportions such that during all or substantially all of the time the concurrent feeding is occurring halogenation of both nitrogen atoms of said 5-hydrocarbyl hydantoin and/or 5,5-dihydrocarbyl hydantoin occurs and resultant halogenated product precipitates in the liquid phase of an aqueous reaction mixture, and in which the pH of said liquid phase is continuously or substantially continuously maintained in the range of about 2.0 to about 8.0 during all or substantially all of the time the concurrent feeding is occurring.