US4206148A
Expired / Lapsed
US
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Process for the dehalogenation of halogen-containing aromatic compounds
Assignee: Bayer CropScience SA
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Filing: 1978-09-12
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Granted: 1980-06-03
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Expires: 1998-09-12
Abstract
Abstract A process for the dehalogenation of halogen-containing aromatic compounds takes place in the vapor phase, at a temperature of between 280 DEG and 420 DEG C., by the action of hydrogen in the presence of a controlled-action hydrogenation catalyst deposited on an alumina-based support wherein the support used is modified, at least on the surface, by the incorporation of a metal in the form of a salt or an oxide, this incorporation consisting in treating the support with the said metal salt or metal oxide and then carrying out a calcination at a temperature ranging from about 500 DEG to 1,000 DEG C.
Inventors
- 👤 Georges Biola
- 👤 Jean Font
- 👤 Jean C. Daumas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:29
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/70; B01J23/76; B01J23/38; B01J23/48; B01J23/50; B01J23/54; B01J23/66; B01J23/74; B01J23/89
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
128 words
Process for the dehalogenation of halogen-containing aromatic amines, which leads to the preferential production of derivatives carrying a smaller number of halogen atoms, at least one of which is substituted in the meta position relative to the amino group, in the vapour phase and at a temperature of between 280° and 420° C., by the action of hydrogen in the presence of a controlled-action hydrogenation catalyst deposited on an alumina-based support, wherein the support used is modified, at least on the surface, by the incorporation of a metal in the form of a salt or an oxide, this incorporation consisting in treating the support with the said metal salt or metal oxide and then carrying out a calcination at a temperature ranging from about 500° to 1,000° C.
Claim 2
Dependent Claim
128 words
Process for the dehalogenation of halogen-containing aromatic amines, which leads to the preferential production of derivatives carrying a smaller number of halogen atoms, at least one of which is substituted in the meta position relative to the amino group, in the vapour phase and at a temperature of between 280° and 420° C., by the action of hydrogen in the presence of a controlled-action hydrogenation catalyst deposited on an alumina-based support, wherein the support used is modified, at least on the surface, by the incorporation of a metal in the form of a salt or an oxide, this incorporation consisting in treating the support with the said metal salt or metal oxide and then carrying out a calcination at a temperature ranging from about 500° to 1,000° C.
Claim 3
Dependent Claim
27 words
Process according to claim 1, wherein the support modified in this way contains from 0.2 to 30% by weight of incorporated metal, relative to the initial support.
Claim 4
Dependent Claim
27 words
Process according to claim 2, wherein the support modified in this way contains from 5 to 20% by weight of incorporated metal, relative to the initial support.
Claim 5
Dependent Claim
30 words
Process according to claim 1, wherein the metal incorporated is chosen from the group consisting of alkali and alkaline earth metals, iron, nickel, cobalt, zinc copper, chromium, molybdenum and tungsten.
Claim 6
Dependent Claim
14 words
Process according to claim 4, wherein the metal incorporated in the support is magnesium.
Claim 7
Dependent Claim
18 words
Process according to one of claims 1 to 5, wherein the active phase of the catalyst is copper.
Claim 8
Dependent Claim
18 words
Process according to one of claims 1 to 5, wherein the active phase of the catalyst is silver.
Claim 9
Dependent Claim
28 words
Process according to claim 1, wherein the support is treated with the metal salt or metal oxide by impregnating alumina using the said metal salt or metal oxide.
Claim 10
Dependent Claim
47 words
Process according to claim 1, wherein the support is treated with the metal salt or metal oxide by mixing an aluminium salt with a metal salt, shaping the mixture, gelling it by neutralising the resulting compound, and dispersing it as fine spherical droplets in a hot hydrocarbon.
Claim 11
Dependent Claim
21 words
Process according to claim 1, wherein the treated support is calcined at a temperature ranging from about 800° to 1,000° C.
Claim 12
Dependent Claim
27 words
Process according to claim 1, wherein the initial aromatic amines, containing several halogen atoms, are anilines containing two, three or four halogen atoms on the phenyl nucleus.
Claim 13
Dependent Claim
12 words
Process according to claim 11, wherein the halogen atoms are chlorine atoms.
Claim 14
Dependent Claim
40 words
Process according to claim 1, wherein the initial aromatic amines, containing several halogen atoms, are prepared in situ by introducing, into the dehalogenation zone, the aromatic nitro compounds, containing several halogen atoms, which are used to obtain the said amines.
Claim 15
Dependent Claim
27 words
Process according to claim 1, wherein the unconverted initial amine or halogenoamines produced by the reaction are recycled, in whole or in part, into the reaction zone.
Claim 16
Dependent Claim
33 words
Process according to claim 1, wherein the gaseous effluent produced by the reaction is brought into contact with a liquid or vapour which is at a substantially lower temperature than the said effluent.
Claim 17
Dependent Claim
16 words
Process according to claim 15, wherein the liquid or vapour is water or an organic solvent.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-06-03 | 1983-12-03 | 1984-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-03 | 1987-12-03 | 1988-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-03 | 1991-12-03 | 1992-06-03 | $7700.00 | Window Closed / Lapsed |