US4319035A
Expired / Lapsed
US
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Process for recycling noble metal catalysts used for the manufacture of aromatic urethanes
Assignee: BASF SE
•
Filing: 1980-11-10
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Granted: 1982-03-09
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Expires: 2000-11-10
Abstract
Abstract A process for the preparation of an aromatic urethane by the reaction in solution of an aromatic nitro compound or aromatic amine in the presence of an oxidation agent, with a hydroxyl compound and carbon monoxide in the presence of a noble metal catalyst, the improvement which comprises (a) treating the reaction solution, containing the noble metal catalyst, after the urethane formation is complete, with hydrogen (b) separating the noble metal in elementary form from the reaction solution, and (c) reusing the noble metal, together with a hydrohalic acid, as a catalyst.
Inventors
- 👤 Franz Merger
- 👤 Friedrich Towae
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:32
CPC Classifications
B; B01; B01J; B01J27/00; B01J27/28; B01J27/32
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
95 words
In a process for the preparation of an aromatic urethane by the reaction in solution of an aromatic nitro compound or an aromatic amine and an oxidation agent with a hydroxyl compound and carbon monoxide, in the presence of a noble metal catalyst selected from the group consisting of palladium of chemical compounds thereof, the improvement which comprises (a) treating a reaction solution of the urethane, containing the noble metal catalyst, with hydrogen after urethane formation is complete, and (b) separating the noble metal catalyst, precipitated in its elementary form, from the urethane reaction solution.
Claim 2
Dependent Claim
95 words
In a process for the preparation of an aromatic urethane by the reaction in solution of an aromatic nitro compound or an aromatic amine and an oxidation agent with a hydroxyl compound and carbon monoxide, in the presence of a noble metal catalyst selected from the group consisting of palladium of chemical compounds thereof, the improvement which comprises (a) treating a reaction solution of the urethane, containing the noble metal catalyst, with hydrogen after urethane formation is complete, and (b) separating the noble metal catalyst, precipitated in its elementary form, from the urethane reaction solution.
Claim 3
Dependent Claim
24 words
The process of claim 1 with an additional step of: (c) recycling the noble metal, together with a hydrohalic acid, to the reaction solution.
Claim 4
Dependent Claim
36 words
The process of claim 1 which comprises treating the reaction solution, containing the noble metal catalyst, with hydrogen at a temperature between 50° C. and 150° C. and a pressure between 2 bars and 50 bars.
Claim 5
Dependent Claim
30 words
The process of claim 2 wherein the hydrohalic acid is hydrogen chloride, hydrogen bromide or compounds forming hydrogen chloride or hydrogen bromide under the reaction conditions of the urethane manufacture.
Claim 6
Dependent Claim
13 words
The process of claim 1 wherein the noble metal catalyst is palladium chloride.
References Cited (Backward Citations)
US2963444A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-03-08 | 1985-09-07 | 1986-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-03-08 | 1989-09-07 | 1990-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-03-08 | 1993-09-07 | 1994-03-09 | $7700.00 | Window Closed / Lapsed |