US4855518A
Expired / Lapsed
US
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Method for producing p-alkylstyrene
Assignee: Eneos Corp
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Filing: 1988-07-19
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Granted: 1989-08-08
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Expires: 2008-07-19
Abstract
Abstract A method for producing p-alkylstyrene which is characterized in that side reaction scarcely occurs, catalyst and unreacted material are easily recovered for the reuse, the p-position selectivity is excellent and yield of aimed product is high. In the method, monoalkylbenzene having an alkyl group with 3 or more carbon atoms is reacted with acetaldehyde in the presence of hydrogen fluoride catalyst under the conditions of a temperature of 0° C. or lower, a molar ratio of 2 to 100 in "alkylbenzene/acetaldehyde", the other molar ratio of 1.7 to 300 in "hydrogen fluoride/acetaldehyde", the proportion of hydrogen fluoride to the sum of hydrogen fluoride and water in the reaction system of 65% by weight or higher, and the concentration of acetaldehyde in the reaction system of 1.0% by weight or lower to obtain 1,1-bis(p-alkylphenyl)ethane, and then subjecting it to catalytic cracking at a temperature in the range of 200° to 650° C. in the presence of an acid catalyst.
Inventors
- 👤 Isoo Shimizu
- 👤 Yuuichi Tokumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 04:48
CPC Classifications
C; C07; C07C; C07C15/00; C07C15/40; C07C15/42; C07C15/44; C07C15/46; C07C2/00; C07C2/86; C07C2/862; C07C2/867; C07C4/00; C07C2527/00; C07C2527/06; C07C2527/08; C07C2527/12; C07C2527/1206
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
146 words
A method for producing p-alkylstyrene which is characterized in that monoalkylbenzene having an alkyl substituent group with 3 or more carbon atoms is reacted with acetaldehyde in the presence of hydrogen fluoride catalyst under the conditions of a temperature of 0° C. or lower, a molar ratio of 2 to 100 in "alkylbenzene/acetaldehyde" to be fed to the reaction system, the other molar ratio of 1.7 to 300 in "hydrogen fluoride/acetaldehyde" to be fed to the reaction system, the proportion of hydrogen fluoride to the sum of hydrogen fluoride and water in the reaction system of 65% by weight or higher, and the concentration of acetaldehyde in the reaction system of 1.0% by weight or lower to obtain 1,1-bis(p-alkylphenyl)ethane, and then subjecting the obtained 1,1-bis(p-alkylphenyl)ethane to catalytic cracking at a temperature in the range of 200° to 650° C. in the presence of an acid catalyst.
Claim 2
Independent Claim
146 words
A method for producing p-alkylstyrene which is characterized in that monoalkylbenzene having an alkyl substituent group with 3 or more carbon atoms is reacted with acetaldehyde in the presence of hydrogen fluoride catalyst under the conditions of a temperature of 0° C. or lower, a molar ratio of 2 to 100 in "alkylbenzene/acetaldehyde" to be fed to the reaction system, the other molar ratio of 1.7 to 300 in "hydrogen fluoride/acetaldehyde" to be fed to the reaction system, the proportion of hydrogen fluoride to the sum of hydrogen fluoride and water in the reaction system of 65% by weight or higher, and the concentration of acetaldehyde in the reaction system of 1.0% by weight or lower to obtain 1,1-bis(p-alkylphenyl)ethane, and then subjecting the obtained 1,1-bis(p-alkylphenyl)ethane to catalytic cracking at a temperature in the range of 200° to 650° C. in the presence of an acid catalyst.
Claim 3
Dependent Claim
30 words
The method for producing p-alkylstyrene in claim 1, wherein isobutylbenzene is reacted with acetaldehyde to obtain 1,1-bis(p-isobutylphenyl)ethane and said 1,1-bis(p-isobutylphenyl)ethane is catalytically cracked in the presence of an acid catalyst.
Claim 4
Dependent Claim
91 words
The method for producing p-alkylstyrene in claim 1, wherein monoalkylbenzene is reacted with acetaldehyde under the conditions that said molar ratio of "alkylbenzene/acetaldehyde" to be fed to the reaction system is 2.2 to 50, said the other molar ratio of "hydrogen fluoride/acetaldehyde" to be fed to the reaction system is 2.7 to 100, the proportion of hydrogen fluoride to the sum of hydrogen fluoride and water in the reaction system is 75% by weight or higher, and the concentration of acetaldehyde in the reaction system is 0.5% by weight or lower.
Claim 5
Dependent Claim
32 words
The method for producing p-alkylstyrene in claim 1, wherein said acid catalyst is one member selected from the group consisting of protonic acids, solid acids and protonic acids carried on solid acids.
Claim 6
Dependent Claim
34 words
The method for producing p-alkylstyrene in claim 4, wherein catalytic cracking is carried out in a gas phase in the presence of a solid acid and/or a protonic acid carried on a solid acid.
Claim 7
Dependent Claim
37 words
The method for producing p-alkylstyrene in claim 1, wherein said catalytic cracking is carried out by diluting 1,1-bis(p-alkylphenyl)ethane by adding an inert gas so that the molar ratio as represented by "inert gas/1,1-bis(p-alkylphenyl)ethane" is 50 or higher.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-07 | 1993-02-06 | 1993-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-07 | 1997-02-06 | 1997-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-07 | 2001-02-06 | 2001-08-08 | $7700.00 | Window Closed / Lapsed |