Claims
- 1. A process for the preparation of halogen substituted phthalic anhydrides of the formula: ##STR7## where each X is independently F--, Cl--, Br-- or I--, and n is 1 or 2, which comprises reacting chlorine, in the absence of an acid acceptor, with a halogen substituted hexa- or tetra-hydrophthalic anhydride reactant of the formula: ##STR8## where Q is monohalo and is the same as X or is gem-dihalo, wherein at least one halogen is the same as X, and n is the same number as in formula I, with the proviso that each monohalo is directly attached to a double bond carbon and each gem-dihalo is directly attached to a non-double bond carbon, at a temperature of 200.degree.-500.degree. C.
- 2. A process according to claim 1 wherein X is F--, Cl--, or Br--.
- 3. A process according to claim 2, carried out in the vapor phase.
- 4. A process according to claim 2, carried out in the liquid phase at a temperature of about 200.degree. to 300.degree. Celsius.
- 5. A process according to claim 2 carried out in the presence of an activated carbon catalyst.
- 6. A process according to claim 5 carried out in the vapor phase.
- 7. A process according to claim 5 carried out in the liquid phase at a temperature of about 200.degree. to 300.degree. Celsius.
- 8. A process according to claim 7 wherein each Q is monohalo.
- 9. A process according to claim 2 wherein the reactant is 4-chlorotetrahydrophthalic anhydride.
- 10. A process according to claim 2 wherein the reactant is 3-chlorotetrahydrophthalic anhydride.
- 11. A process according to claim 2 wherein the reactant is 4-fluorotetrahydrophthalic phthalic anhydride.
- 12. A process according to claim 2 wherein the reactant is 4-bromotetrahydrophthalic anhydride.
- 13. A process according to claim 2 wherein the reactant is 4,5-dichlorotetrahydrophthalic anhydride.
- 14. A process according to claim 2 wherein the reactant is 4,5-difluorotetrahydrophthalic anhydride.
- 15. A process according to claim 2 wherein the reactant is 4-chloro-5-fluorotetrahydrophthalic anhydride.
- 16. A process according to claim 1, wherein at least one Q is gem-dihalo.
- 17. A process according to claim 16 wherein the reactant is 4,4-difluorohexahydrophthalic anhydride.
- 18. A process according to claim 16 carried out in the vapor phase.
- 19. A process according to claim 5 wherein each Q is monohalo.
- 20. A process according to claim 5 wherein at least one Q is gem-dihalo.
- 21. A process according to claim 19 carried out in the liquid phase.
- 22. A process according to claim 19 carried out in the vapor phase.
- 23. A process according to claim 22 wherein the reactant is 4-chlorotetrahydrophthalic anhydride.
- 24. A process according to claim 22 wherein the reactant is 3-chlorotetrahydrophthalic anhydride.
- 25. A process according to claim 22 wherein the reactant is 4-fluorotetrahydrophthalic anhydride.
- 26. A process according to claim 22 wherein the reactant is 4-bromotetrahydropthalic anhydride.
- 27. A process according to claim 22 wherein the reactant is 4,5-dichlorotetrahydrophthalic anhydride.
- 28. A process according to claim 22 wherein the reactant is 4,5-difluorotetrahydrophthalic anhydride.
- 29. A process according to claim 22 wherein the reactant is 4-chloro-5-fluorotetrahydrophthalic anhydride.
- 30. A process according to claim 20 wherein the reactant is 4,4-difluorohexahydrophthalic anhydride, and the process is carried out in the vapor phase.
- 31. A process for the preparation of 4-chlorophthalic anhydride which comprises mixing and reacting chlorine gas and 4-chloro-1,2,3,6-tetrahydrophthalic anhydride vapors, in the absence of an acid acceptor, at a temperature of about 240.degree. to 300.degree. Celsius.
- 32. A process according to claim 31 wherein a mixture of chlorine gas and 4-chloro-1,2,3,6-tetrahydrophthalic anhydride vapors are passed through a bed of activated carbon at a temperature of about 240.degree. to 300.degree. Celsius.
- 33. A process for the preparation of 4-fluorophthalic anhydride which comprises reacting a mixture of chlorine gas and 4,4-difluorohexahydrophthalic anhydride vapors at a temperature of about 240.degree. to 300.degree. Celsius, in the absence of an acid acceptor, in the presence of activated carbon.
BACKGROUND OF THE INVENTION
This application is a continuation-in-part application of copending applications Ser. No. 160,033 for "Improved Dehydrogenation Procedure": and application Ser. No. 160,034 for "Selective Dehydrogenation with Chlorine," both now abandoned, both filed Feb. 24, 1988.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4559405 |
Telschow |
Dec 1985 |
|
4560773 |
Telschow |
Dec 1985 |
|
Non-Patent Literature Citations (1)
Entry |
Ohkrtsu et al, J. Japan Petrol. Inst., vol. 27 (1979) pp. 164-169. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
160033 |
Feb 1988 |
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