US4046807A
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Process for preparing acetic anhydride
Assignee: Hoechst AG
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Filing: 1975-10-24
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Granted: 1977-09-06
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Expires: 1995-10-24
Abstract
Abstract Process for preparing acetic anhydride from acetic acid methyl ester and carbon monoxide in the presence of catalysts containing noble metals of the 8 th sub-group of the periodic table or their compounds as well as iodine and/or iodine compounds.
Inventors
- 👤 Herbert Kuckertz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:04
CPC Classifications
B; B01; B01J; B01J27/00; B01J27/06; B01J27/08; B01J23/00; B01J23/38; C; C07; C07C; C07C51/00; C07C51/54; C07C51/56
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
63 words
A process for the preparation of acetic anhydride which comprises reacting a mixture consisting essentially of acetic acid methyl ester and carbon monoxide at a pressure of 1 to 500 bar and at temperature of from 50 to 250° C and carrying out said reaction in the presence of a catalyst containing a noble metal of the 8th subgroup of the Periodic Table.
Claim 2
Dependent Claim
63 words
A process for the preparation of acetic anhydride which comprises reacting a mixture consisting essentially of acetic acid methyl ester and carbon monoxide at a pressure of 1 to 500 bar and at temperature of from 50 to 250° C and carrying out said reaction in the presence of a catalyst containing a noble metal of the 8th subgroup of the Periodic Table.
Claim 3
Dependent Claim
19 words
The process of claim 1, which comprises carrying out the reaction at a pressure of 10 to 300 bar.
Claim 4
Dependent Claim
19 words
The process of claim 1 which comprises carrying out the reaction at a temperature of 120° to 200° C.
Claim 5
Dependent Claim
16 words
The process of claim 1, which comprises carrying out the reaction in the presence of hydrogen.
Claim 6
Dependent Claim
12 words
The process of claim 1, wherein the noble metal catalyst contains rhodium.
Claim 7
Dependent Claim
21 words
The process of claim 1, wherein the catalyst contains a member selected from the group consisting of iodine and iodine compounds.
Claim 8
Dependent Claim
23 words
The process of claim 1, wherein the catalyst contains a member selected from the group consisting of alkyl iodide and acyl iodide compounds.
Claim 9
Dependent Claim
64 words
A process for the preparation of acetic anhydride which comprises reacting a mixture consisting essentially of acetic acid methyl ester and carbon monoxide at a temperature of about 120° to 200° C and a pressure of up to 200 bar and carrying out said reaction in the presence of a catalyst which contains a noble metal of the eighth subgroup of the Periodic Table.
Claim 10
Dependent Claim
64 words
A process for the preparation of acetic anhydride which comprises reacting a mixture consisting essentially of acetic acid methyl ester and carbon monoxide at a temperature of about 120° to 200° C and a pressure of up to 200 bar and carrying out said reaction in the presence of a catalyst which contains a noble metal of the eighth subgroup of the Periodic Table.
Claim 11
Dependent Claim
21 words
The process of claim 8 wherein the selectivity of the reaction to the production of acetic anhydride is more than 90%.
Claim 12
Dependent Claim
15 words
The process of claim 8 wherein the reaction is carried out in about 3 hours.
Claim 13
Dependent Claim
15 words
The process of claim 8 wherein the reaction is carried out in about 5 hours.
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) | 1980-09-05 | 1981-03-07 | 1981-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-05 | 1985-03-07 | 1985-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-05 | 1989-03-07 | 1989-09-06 | $7700.00 | Window Closed / Lapsed |