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US4497747A
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Process for making acetic anhydride
Assignee: Hoechst AG
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Filing: 1983-07-19
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Granted: 1985-02-05
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Expires: 2003-07-19
Abstract
Abstract The disclosure relates to a process for making acetic anhydride by reacting methyl acetate and/or dimethylether with carbon monoxide, if desired in admixture with up to 20 volume % hydrogen, under practically anhydrous conditions at temperatures of 120 DEG to 270 DEG C., under pressures of 1 to 500 bars in the presence of a catalyst system containing nickel or a nickel compound, an organic iodine or bromine compound as well as a tertiary or quaternary organic phosphorus compound. More particularly, a catalyst system containing a titanium or zirconium compound as an additional constituent is used.
Inventors
- 👤 Wilhelm Vogt
- 👤 Hermann Glaser
- 👤 Erhard Jagers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:52
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/54; C07C51/56
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
78 words
A process for making acetic anhydride by reacting methyl acetate or dimethylether with carbon monoxide unter practically anhydrous conditions at temperatures of 120° to 270° C., under pressures of 1 to 500 bars in the presence of a catalyst system containing nickel or a nickel compound, an organic iodine or bromine compound as well as a tertiary or quaternary organic phosphorus compound, which comprises using a catalyst system containing a titanium or zirconium compound as an additional constituent.
Claim 2
Dependent Claim
78 words
A process for making acetic anhydride by reacting methyl acetate or dimethylether with carbon monoxide unter practically anhydrous conditions at temperatures of 120° to 270° C., under pressures of 1 to 500 bars in the presence of a catalyst system containing nickel or a nickel compound, an organic iodine or bromine compound as well as a tertiary or quaternary organic phosphorus compound, which comprises using a catalyst system containing a titanium or zirconium compound as an additional constituent.
Claim 3
Dependent Claim
18 words
A process as claimed in claim 1, wherein the catalyst contains an oxyalkyl compound of titanium or zirconium.
Claim 4
Dependent Claim
28 words
A process as claimed in claim 1, wherein the methyl acetate or dimethylether/nickel(compound)/iodine or bromine compound/phosphorus compound/titanium or zirconium compound are used in a molar ratio of 1:(0.001-0.1):(0.01-1):(0.005-1):(0.0005-0.1).
Claim 5
Dependent Claim
21 words
A process as claimed in claim 1, wherein carbon monoxide is used in admixture with up to 20 volume % hydrogen.
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) | 1988-02-05 | 1988-08-06 | 1989-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-05 | 1992-08-06 | 1993-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-05 | 1996-08-06 | 1997-02-05 | $7700.00 | Window Closed / Lapsed |