| PATENT ASSIGNEE'S COUNTRY | USA |
| UPDATE | 09.01 |
| PATENT GRANT DATE | 04.09.01 |
| PATENT TITLE |
Process for producing hexabromocyclododecane |
| PATENT ABSTRACT |
This invention relates to the production of an hexabromocyclododecane product, which process comprises brominating cyclododecatriene in the presence of a 1,4-dioxane and water based solvent and from about 0.5 to about 30 wt % bromide ion in the liquid phase of the reaction mass. Optional post-reaction heat treatment in a finishing step increases process yields if needed. The hexabromocyclododecane product is unrecrystallized and contains no more than about 1.5 wt % tetrabromocyclododecene impurities. |
| PATENT INVENTORS | Kendall; John K. (Magnolia, AR); Aplin; Jeffrey T. (Baton Rouge, LA) |
| PATENT ASSIGNEE | Albemarle |
| PATENT FILE DATE | 18.08.99 |
| PATENT CLAIMS |
1. A process for the production of a hexabromocyclododecane, which process comprises brominating cyclododecatriene in a solvent comprised of 1,4-dioxane and water and in the presence of from about 0.5 to about 30 wt % bromide, the wt % being based on the total weight of the liquid portion of the reaction mass. 2. The process of claim 1 wherein the bromide ion is derived from a bromide source selected from the group consisting of alkali metal bromideion, alkaline earth metal bromide, organic bromide and mixtures of any two or more of the foregoing. 3. The process of claim 2 wherein the bromide ion is derived from a bromide source selected from the group consisting of hydrogen bromide, sodium bromide, lithium bromide, and mixtures of any two or more of the foregoing. 4. The process of claim 2 wherein the bromide source is selected from hydrogen bromide, lithium bromide or mixtures of the two. 5. The process of claim 2 wherein the bromide source is hydrogen bromide. 6. The process of claim 1 wherein the bromide ion is present in an amount within the range of from about 3 to about 30 wt %. 7. The process of claim 1 wherein the 1,4-dioxane and water solvent contains no more than about 40 wt % water, the wt % being based on the total weight of the solvent. 8. The process of claim 7 wherein the 1,4-dioxane and water solvent contains up to about 20 wt % water and from about 80 to about 95 wt % 1,4-dioxane. 9. A process for the production of a hexabromocyclododecane, which process comprises brominating cyclododecatriene in a 1,4-dioxane and water solvent. 10. The process of claim 9 wherein the 1,4-dioxane and water solvent contains no more than about 40 wt % water, the wt % being based on the total weight of the solvent. 11. The process of claim 9 wherein the 1,4-dioxane and water solvent contains up to about 20 wt % water and from about 80 to about 95 wt % 1,4-dioxane. 12. A process for the production of a hexabromocyclododecane, which process comprises brominating cyclododecatriene in a solvent which contains less than 5 wt % alcohol or reactive species and which is comprised of 1,4-dioxane and water. 13. The process of claim 12 wherein the solvent contains no more than about 40 wt % water, the wt % being based on the total weight of the solvent. 14. The process of claim 13 wherein the solvent contains up to about 20 wt % water and from about 80 to about 95 wt % 1,4-dioxane. 15. The process of claim 1 wherein the solvent contains less than about 5 wt % alcohol or reactive species. -------------------------------------------------------------------------------- |
| PATENT EXAMPLES |
EXAMPLE I A 5L multi-neck, fully-jacketed round bottom flask was charged with 3130 g of neat 1,4-dioxane and 870 g of aqueous 60% HBr (6.44 mol HBr). Cyclododecatriene (CDT) (630 g, 3.89 mol, 5.5:1 loading) and bromine (1959 g, 12.24 mol, 5% mol excess) were primed for subsurface co-feed. Bromine (90 g, 0.56 mol) was pre-charged to the reactor before beginning the CDT feed. Feed rates for the CDT and bromine were adjusted so that both feeds ended simultaneously after 105 minutes. A cooling system was used to insure that the reaction temperature did not exceed 40.degree. C. during the feeding period. At feed completion, it was determined that a thermal finishing step would be suitable. Thus, hot glycol was circulated to warm the reaction mass to approximately 90.degree. C. where it was maintained for approximately 120 minutes. After this period the reaction mass was allowed to cool to ambient temperature. The reaction mass was centrifuged in six drops, with each drop being washed with 300 g of a 90 wt % 1,4-dioxane in water mix. The combined solids from each drop were then slurried in two portions each in 2 liters 0.05% ammonium hydroxide. Vacuum filtration, and washing with water was followed by oven drying overnight at 95.degree. C. gave a white hexabromocyclododecane product (1765 g, 70% yield). The yield was based on the moles of hexabromocyclododecane product recovered per mole of cyclododecatriene used in the reaction. The following Table gives an analysis of the hexabromocyclododecane product produced by the procedure of Example I. The Table also gives an analysis of a hexabromocyclododecane product produced conventionally using isobutyl alcohol as the process solvent. TABLE HBCD Product HBCD Product HBCD Product from Isobutyl Analysis from Example Alcohol Process alpha 16.3 wt % 13.1 wt % beta 12.3 wt % 6.1 wt % tetra 0.2 wt % 4.7 wt % gamma 71.1 wt % 75.5 wt % total HBCD* 99.7 wt % 94.9 wt % melt point** 181-194 181-195 *Total HBCD is the amount of hexabromocyclododecane in the hexabromocyclododecane product. **Visual Melt point is measured as .degree. C. |
| PATENT PHOTOCOPY | Available on request |
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