# US 5,352,844 A · Isolation of partially brominated diphenyl ether mixtures in crystalline form with higher melting range > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,352,844 A - Document ID: US5352844A - Status: Granted - Kind: A - Application number: 08/188,360 - Filed: 1994-01-27 - Granted: 1994-10-04 - Earliest claimed: 1992-06-04 - Assignees: Great Lakes Chemical Corporation - Inventors: Bhabatosh Bhattacharya; Wayne C. Muench - Web page: https://patentgrep.com/patent/US5352844A ## CPC - C07C 41/40: by change of physical state, e.g. by crystallisation - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS ## Abstract This invention relates to a process for isolation of partially brominated diphenyl ether mixtures ("Octabrom") having an average bromine content of 7.2-8.5. The process comprises: (i) adding a C.sub.1 -C.sub.4 alkanol to the Octabrom in solution in an organic solvent; (ii) maintaining the contact of the alkanol with Octabrom in the organic solvent for that period of time which is sufficient to allow the Octabrom to precipitate in crystalline form, making a slurry; and (iii) recovering the final Octabrom from the slurry. ## Claims ### Claim 1 A method for the isolation of a solid partially brominated diphenyl ether product from a mixture of partially bromnated diphenyl ethers having an average of from about 7.2 to ab out 8.5 bromine atoms per molecule of diphenyl ether, the method comprising: a. providing a mixture of partially brominated diphenyl ethers, wherein said mixture has been removed form its bromination medium; b. dissolving the mixture in an organic solvent selected from the group consisting of benzene, toluene, and xylenes, or mixtures thereof, at a temperature sufficiently high for the partially brominated diphenyl ethers and solvent to form a solution, c. contacting the solution of step b with a C.sub.1 -C.sub.4 alkanol; d. maintaining the contact of step c, for a sufficient time to allow said diphenyl ether product to precipitate out; and e. recovering the precipitate. ### Claim 2 (depends on 1) The method of claim 1 in which step d, also comprises cooling the mixture of step c. ### Claim 3 (depends on 1) The method of claim 1 in which the mixture of partially brominated diphenyl ethers contains ethers selected from the group consisting of pentabromodiphenyl ether, hexabromodiphenyl ether, heptabromodiphenyl ether, octabromodiphenyl ether, nonabromodiphenyl ether or decabromodiphenyl ether, and mixtures thereof. ### Claim 4 (depends on 1) The method of claim 1 in which the C.sub.1 -C.sub.4 alkanol is selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, isobutanol and t-butanol, or mixtures thereof. ### Claim 5 (depends on 4) The method of claim 4 in which the alkanol is selected from the group consisting of methanol, ethanol, or mixtures thereof. ### Claim 6 (depends on 5) The method of claim 5 in which the alkanol is methanol. ### Claim 7 (depends on 1) The method of claim 1 and which includes maintaining the contact for between about 1 to about 8 hours prior to the recovering step e. ### Claim 8 (depends on 7) The method of claim 7 in which said maintaining is between about 2 hours and about 6 hours. ### Claim 9 (depends on 7) The method of claim 7 in which said maintaining is at a temperature of between about 25.degree. C. and about 85.degree. C. ### Claim 10 (depends on 9) The method of claim 9 in which said maintaining is at a temperature of about 25.degree. C. ### Claim 11 A method for the isolation of a solid partially brominated diphenyl ether product from a mixture of partially brominated diphenyl ethers having an average of from about 7.2 to about 8.5 bromine atoms per molecule of diphenyl ether, the method comprising: a. providing a solution of the partially brominated diphenyl ethers in an organic solvent at a temperature sufficiently high for the partially brominated diphenyl esters to be dissolve din the organic solvent; b. contacting the solution of step a, with a C.sub.1 -C.sub.4 alkanol; c. maintaining the contact of step b, for a sufficient time to allow said diphenyl ether product to precipitate out; and d. recovering the precipitate; wherein the organic solvent is selected from the group consisting of benzene, toluene, and xylenes, or mixtures thereof. ### Claim 12 (depends on 11) The method of claim 11 in which the organic solvent is toluene. ### Claim 13 A method for isolating a solid dipheny ether product having an average of from about 7.2 to about 8.5 bromine atoms per molecule of diphenyl ether from a mixture of partially brominated diphenyl ethers, wherein said mixture has been removed from its bromination medium, the method including contacting said mixture of partially brominated diphenyl ethers with a C.sub.1 -C.sub.4 alkanol to form a product mixture and recovering said product from said product mixture, wherein the improvement comprises: prior to said contacting of a C.sub.1 -C.sub.4 alkanol, providing a solution of said mixture of partially brominated diphenyl ethers in an organic solvent selected from the group consisting of benzene, toluene, and xylenes, or mixtures thereof, at a temperature sufficiently high for said mixture of partially brominated diphenyl ethers to be dissolved in said organic solvent. ### Claim 14 (depends on 13) The improvement of claim 13 in which the recovering comprises precipitating out the diphenyl ether product from said product mixture. ### Claim 15 (depends on 13) The improvement of claim 13 in which the mixture of partially brominated diphenyl ethers contains ethers selected from the group consisting of pentabromodiphenyl ether, hexabromodiphenyl ether, heptabromodiphenyl ether, octabromodiphenyl ether, nonabromodiphenyl ether and decabromodiphenyl ether, or mixtures thereof. ### Claim 16 (depends on 13) The improvement of claim 13 in which the C.sub.1 -C.sub.4 alkanol is selected from tile group consisting of methanol, ethanol, propanol, isopropanol, butanol, isobutanol and t-butanol, or mixtures thereof. ### Claim 17 (depends on 16) The improvement of claim 16 in which the alkanol is selected from the group cons]sting of methanol, ethanol, or mixtures thereof. ### Claim 18 (depends on 17) The improvement of claim 17 in which the alkanol is methanol. ### Claim 19 (depends on 13) The improvement of claim 13 which includes maintaining said product mixture for between about 1 hour to abut 8 hours prior to the recovering of said product. ### Claim 20 (depends on 19) The improvement of claim 19 in which said maintaining is for between about 2 hours and about 6 hours. ### Claim 21 (depends on 19) The improvement of claim 19 in which said maintaining is at a temperature of between about 25.degree. C. and about 85.degree. C. ### Claim 22 (depends on 19) The improvement of claim 19 in which said maintaining is at a temperature of about 25.degree. C. ### Claim 23 (depends on 13) The improvement of claim 13 in which said recovering includes adding seed to said product mixture. ### Claim 24 A method for isolating a solid diphenyl ether product having an average of from about 7.2 to about 8.5 bromine atoms per molecule of diphenyl ether from a mixture of partially brominated diphenyl ethers, the method including contacting said mixture of partially brominated diphenyl ethers with a C.sub.1 -C.sub.4 alkanol to form a product mixture and recovering said product from said product mixture, wherein the improvement comprises: prior to said contacting of a C.sub.1 -C.sub.4 alkanol, providing a solution of said mixture of partially brominated diphenyl ethers in an organic solvent at a temperature sufficiently high for said mixture of partially brominated diphenyl ethers to be dissolved in said organic solvent, wherein the organic solvent is selected from the group consisting of benzene, toluene, and xylenes, or mixtures thereof. ### Claim 25 (depends on 24) The improvement of claim 24 in which the organic solvent is toluene. ### Claim 26 A method for the isolation of a solid partially brominated diphenyl ether product from a mixture of partially brominated diphenyl ethers having an average of from about 7.2 to about 8.5 bromine atom per molecule of diphenyl ether, the method comprising: a. brominating diphenyl ether in liquid bromine in the presence of a bromination catalyst to afford a mixture of partially brominated diphenyl ethers; b. dissolving said mixture in an organic solvent selected from the group consisting of benzene, toluene, and xylenes, or mixtures thereof, at a temperature sufficiently high for the partially brominated diphenyl ethers to be dissolved in the organic solvent; c. contacting the solution of step (b) with a C.sub.1 -C.sub.4 alkanol; d. maintaining the contact of step (c) for a sufficient time to allow said diphenyl ether product to precipitate out; and e. recovering the precipitate. ### Claim 27 (depends on 26) The method of claim 26 in which step d also comprises cooling the mixture of step c. ### Claim 28 (depends on 26) The method of claim 26 in which the C.sub.1 -C.sub.4 alkanol is selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, isobutanol and t-butanol, or mixtures thereof.