US4264529A
Expired / Lapsed
US
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Method for preparing p-aminophenol
Assignee: Mallinckrodt Chemical Inc
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Filing: 1980-03-24
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Granted: 1981-04-28
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Expires: 2000-03-24
Abstract
Abstract This invention relates to the field of organic chemistry, and more particularly, to a method for the preparation of p-aminophenol.
Inventors
- 👤 Thomas J. Dunn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:33
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/38; B01J23/40; B01J23/42
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
26 words
A method for preparing p-aminophenol which comprises hydrogenating nitrobenzene in an acidic aqueous reaction medium in the presence of a catalyst comprising platinum supported on gamma-alumina.
Claim 2
Independent Claim
26 words
A method for preparing p-aminophenol which comprises hydrogenating nitrobenzene in an acidic aqueous reaction medium in the presence of a catalyst comprising platinum supported on gamma-alumina.
Claim 3
Dependent Claim
38 words
A method as defined by claim 1 wherein the catalyst is prepared by a method which comprises depositing platinum on a support prepared by calcining boehmite at a temperature in the range of 500° C. to 850° C.
Claim 4
Dependent Claim
19 words
A method as defined by claim 2 wherein the boehmite is calcined at a temperature of about 593° C.
Claim 5
Dependent Claim
23 words
A method as defined by claim 2 wherein the catalyst support has a specific surface area of at least 200 m 2 /g.
Claim 6
Dependent Claim
21 words
A method as defined by claim 4 wherein the support has a specific surface area of about 230 m 2 /g.
Claim 7
Dependent Claim
14 words
A method as defined by claim 4 wherein the catalyst contains about 1-10% Pt.
Claim 8
Dependent Claim
14 words
A method as defined by claim 6 wherein the catalyst contains about 3-5% Pt.
Claim 9
Dependent Claim
14 words
A method as defined by claim 1 wherein the catalyst contains about 3% Pt.
Claim 10
Dependent Claim
20 words
A method as defined by claim 1 wherein the hydrogenation is interrupted prior to the consumption of all the nitrobenzene.
Claim 11
Dependent Claim
32 words
In a method for the preparation of p-aminophenol by the catalytic hydrogenation of nitrobenzene in an acidic aqueous reaction medium, the improvement which comprises utilizing a catalyst comprising platinum supported on gamma-alumina.
Claim 12
Dependent Claim
32 words
In a method for the preparation of p-aminophenol by the catalytic hydrogenation of nitrobenzene in an acidic aqueous reaction medium, the improvement which comprises utilizing a catalyst comprising platinum supported on gamma-alumina.
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) | 1984-04-27 | 1984-10-27 | 1985-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-27 | 1988-10-27 | 1989-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-27 | 1992-10-27 | 1993-04-28 | $7700.00 | Window Closed / Lapsed |