Albemarle Corporation

Ethyl Corporation

Edgar E Spielman, Jr

Hassan Y Elnagar

Bruce C Peters

Dustin H Thomas

John Y Lee

Jonathan N Howarth

Robert M Moore, Jr

Robert L Davis

Burnell Lee

William E Moehle

This invention provides a process for the N-halogenation of at least one 5-hydrocarbyl hydantoin and/or at least one 5,5-dihydrocarbyl hydantoin. The process comprises concurrently feeding into a reaction zone (i) water, inorganic base, and 5,5-dimethylhydantoin, 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 the 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 the 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. Also provided by this invention is a composition of matter which is a halogenated 5-hydrocarbyl hydantoin or a halogenated 5,5-dihydrocarbyl hydantoin, which is a mixture of the 1,3-dibromo-, 1,3-dichloro-, and/or N,N'-bromochloro-species of the halogenated hydantoin.

Process for producing N-halogenated hydantoins

The process enables highly effective N-halogenation of a compound having one or more halogenatable amido or imido functional groups in the molecule. The process involves, for example, concurrently feeding into a reactor (i) water, inorganic base, and the compound to be N-halogenated, e.g., a hydantoin, and a feed of (ii) a brominating agent and/or a chlorinating agent. The proportions of these feeds are such that the pH is kept within the range of ca. 5.5-8.5 (preferably 6.5-8.5, and most preferably 6.8-7.2) and one or more of the amido or imido nitrogen atoms is substituted by a bromine or chlorine atom. A feature of the process is that it can be conducted at elevated temperatures as high as about 90&deg; C. without appreciable thermal decomposition of reactants or product. The resultant product continuously precipitates in high yield and purity. Moreover, products can be produced that are very pale yellow to almost pure white in appearance. Further, the process has been found capable of producing 1,3-dibromo-5,5-dimethylhydantoin with far larger particle sizes than previously produced on a commercial basis.

Process for producing N-halogenated organic compounds

Among the enhanced properties of the 1,3-dibromo-5,5-dimethylhydantoins described are their larger average particle sizes, their compactibility even though devoid of a binder, their excellent free-flowing and low-dust properties, and their more appealing aesthetic qualities, as compared to previously known 1,3-dibromo-5,5-dimethylhydantoins. These novel 1,3-dibromo-5,5-dimethylhydantoins can be produced, for example, by concurrently feeding (i) an aqueous solution or slurry formed from an inorganic base and 5,5-dimethylhydantoin, and (ii) a brominating agent, in proportions such that each nitrogen atom is substituted by a bromine atom, thereby forming product which precipitates in an aqueous reaction mixture. The pH of the reaction mixture is maintained in the range of about 5.5 to about 8.5.

1,3-dibromo-5,5-dimethylhydantoin of enhanced properties

This invention relates to a solvent system which is non-flammable and which is comprised of a hydrocarbon solvent having a flash point less than about 38.degree. C. and a second solvent containing at least 90 wt % n-propyl bromide, the second solvent being present in an amount sufficient to obtain no flash point for the solvent system when tested in accordance with ASTM D-93 and the second solvent being the sole halogenated solvent and flash point suppressor in the solvent system.

No flash point solvent system containing normal propyl bromide

This invention relates to a process for preparing DBNPG by brominating pentaerythritol with HBr in the presence of a catalyst and solvent wherein water is present during the process. The reaction mass is neutralized prior to recovery of the DBNPG from the reaction mass.

Growing community of inventors

Baton Rouge, LA, United States of America

Edgar E Spielman, Jr