Processes for preparing 2,5-dichlorophenol
AssigneeMonsanto Technology LLC
InventorsJohn H. Ahn, Don Probst, Kam-To Wan, John Wang
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Abstract
Processes for producing 2,5-dichlorophenol and 3,6-dichloro-2-methoxybenzoic acid are described. Various processes for isomerizing 2,4-dichlorophenol over a zeolite catalyst to form 2,5-dichlorophenol are provided. Processes for preparing 2,5-dichlorophenol including hydroxylating 1,4-dichlorobenzene are also described. The present invention also relates to processes for producing 3,6-dichloro-2-methoxybenzoic acid.
Claims30
A process for producing 2,5-dichlorophenol, the process comprising:
- contacting a feed comprising 2,4-dichlorophenol with a zeolite catalyst in acid form in an isomerization zone to isomerize at least a portion of the 2,4-dichlorophenol to 2,5-dichlorophenol, wherein the zeolite catalyst has a SiO2/Al2O3 mole ratio of no greater than about 35:1.
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8-20. (canceled)
The process of claim 60 wherein the zeolite catalyst comprises at least one alumino-silicate zeolite selected from the group consisting of ZSM zeolites, Beta zeolites, Y zeolites, and mixtures thereof.
The process of claim 60 wherein the zeolite catalyst comprises a HZ SM-5 zeolite, a HZSM-11 zeolite, or a mixture thereof.
The process of claim 60 wherein the zeolite catalyst comprises a desilicated zeolite catalyst.
24-38. (canceled)
A process for producing 2,5-dichlorophenol, the process comprising:
- contacting a feed comprising 2,4-dichlorophenol and 3,4-dichlorophenol with a zeolite catalyst in acid form in an isomerization zone to isomerize at least a portion of the 2,4-dichlorophenol to 2,5-dichlorophenol.
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48-50. (canceled)
52-59. (canceled)
A process for producing 2,5-dichlorophenol, the process comprising:
- contacting a feed comprising 2,4-dichlorophenol with a zeolite catalyst in acid form in an isomerization zone to isomerize at least a portion of the 2,4-dichlorophenol to 2,5-dichlorophenol;
- suspending contact of the feed comprising 2,4-dichlorophenol with the zeolite catalyst;
- and
- contacting the zeolite catalyst with steam at a temperature from about 250° C. to about 375° C. to rejuvenate the catalyst.
61-69. (canceled)
Dependencies are inferred from the claim text.