Claims
- 1. A process for the preparation of a dioxydiphthalic anhydride of the formula ##STR11## comprising reacting a dihalo-phthalic anhydride of the formula ##STR12## where Hal is F, Cl, Br or I, with water and an alkali metal compound selected from the group consisting of KF, CsF, and K.sub.2 CO.sub.3, and recovering dioxydiphthalic anhydride.
- 2. A process according to claim 1 wherein the dihalo-phthalic anhydride is 4,5-dichlorophthalic anhydride.
- 3. A process according to claim 1 wherein the dihalo-phthalic anhydride is 4,5-difluorophthalic anhydride.
- 4. A process according to claim 1 carried out neat.
- 5. A process according to claim 1 carried out in the presence of a polar aprotic solvent.
- 6. A process according to claim 1 wherein the alkali metal compound is potassium fluoride.
- 7. A process according to claim 1 wherein the alkali metal compound is potassium carbonate.
- 8. A process according to claim 1 carried out in the presence of a phase transfer catalyst.
- 9. A process according to claim 5 carried out in the presence of a tetraphenylphosphonium bromide catalyst.
- 10. A process according to claim 4 carried out in the presence of a tetraphenylphosphonium bromide catalyst.
- 11. A process for the preparation of 4,4',5,5'-dioxydiphthalic anhydride comprising reacting a 4,5-dihalophthalic anhydride, wherein halo- is fluoro-, chloro-, or bromo-, with water and an alkali metal compound selected from the group consisting of KF, CsF, and K.sub.2 CO.sub.3 at a temperature of about 150.degree. to 250.degree. Celsius and recovering 4,4',5,5'-dioxydiphthalic anhydride.
- 12. A process for the preparation of 5-chloro-5'-fluoro4,4'-oxydiphthalic anhydride of the formula ##STR13## comprising reacting a mixture of a dihalo-phthalic anhydride of the formula ##STR14## and a dihalophthalic anhydride of the formula ##STR15## with water and an alkali metal compound selected from the group consisting of KF, CsF, and K.sub.2 CO.sub.3 and recovering 5-chloro-5'-fluoro-4,4'-oxydiphthalic anhydride.
- 13. A process for the preparation of a dihalo-oxydiphthalic anhydride of the formula ##STR16## which comprises reacting a dihalo-phthalic anhydride of the formula ##STR17## where Hal is F, Cl, Br or I, with water and an alkali metal compound selected from the group consisting of KF, CsF, and K.sub.2 CO.sub.3 and recovering dihalo-oxydiphthalic anhydride.
- 14. A process according to claim 13 wherein Hal is Cl.
- 15. A process according to claim 13 wherein Hal is F.
Parent Case Info
This is a division of application Ser. No. 07/352,070, filed May 15, 1989, now U.S. Pat. No. 4,943,642.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4697023 |
Schwartz et al. |
Sep 1987 |
|
4837404 |
Schwartz et al. |
Jun 1989 |
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Divisions (1)
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Number |
Date |
Country |
Parent |
352070 |
May 1989 |
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