Patent US3707776A successfully refreshed from Google Patents.
Patent US4554380A successfully refreshed from Google Patents.
US4554380A
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US
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Process for the manufacture of o-toluidine and/or m-toluidine and/or p-toluidine
Assignee: Hoechst AG
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Filing: 1984-08-27
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Granted: 1985-11-19
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Expires: 2004-08-27
Abstract
Abstract The invention provides a process for the manufacture of o-toluidine and/or m-toluidine and/or p-toluidine, which comprises the two following steps (a) and (b): (a) treatment of a toluidine isomer mixture or of the not intended toluidine isomer or of one of the not intended toluidine isomers with an isomerization catalyst selected from the group of synthetic zeolites of the pentasil type, (b) isolation of the intended isomer or one of the intended isomers from the isomer mixture formed in step (a) by selective adsorption to a medium-pore or large-pore zeolite and subsequent desorption, furthermore discharge of the isolated isomer and recycling of the remaining isomer mixture to step (a).
Inventors
- 👤 Hans-Jurgen Arpe
- 👤 Heinz Litterer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:03
CPC Classifications
C; C07; C07C; C07C209/00; C07C209/68
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
65 words
A method for making at least one member selected from the group consisting of o-toluidine, m-toluidine, and p-toluidine, which comprises contacting at least one toluidine isomer other than a toluidine isomer sought to be isolated with an isomerization catalyst selected from the group of synthetic zeolites of the pentasil type, the ions of which are exchanged, at a temperature from 250° C. to 500° C.
Claim 2
Independent Claim
65 words
A method for making at least one member selected from the group consisting of o-toluidine, m-toluidine, and p-toluidine, which comprises contacting at least one toluidine isomer other than a toluidine isomer sought to be isolated with an isomerization catalyst selected from the group of synthetic zeolites of the pentasil type, the ions of which are exchanged, at a temperature from 250° C. to 500° C.
Claim 3
Dependent Claim
16 words
A method as in claim 1 wherein said temperature is from 300° C. to 450° C.
Claim 4
Dependent Claim
42 words
A method as in claim 1 wherein the exchanged ions are cations selected from the group consisting of NA.sup.(+), H.sup.(+), NH 4 .sup.(+), Be 2 (+), Mg 2 (+), Ca 2 (+), and rare earth metal ions, or combinations of these cations.
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) | 1988-11-18 | 1989-05-20 | 1989-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-18 | 1993-05-20 | 1993-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-18 | 1997-05-20 | 1997-11-19 | $7700.00 | Window Closed / Lapsed |