Patent US4002677A successfully refreshed from Google Patents.
US4002677A
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Process for preparing carboxylic acid anhydrides
Assignee: Halcon Research and Development Corp
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Filing: 1975-12-22
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Granted: 1977-01-11
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Expires: 1995-12-22
Abstract
Abstract A carboxylic acid anhydride such as acetic anhydride, is prepared from a carboxylate ester or a hydrocarbyl ether in carbonylation processes comprising the use of an iodide, carbon monoxide and a nickel-chromium catalyst in the presence of a tin promoter.
Inventors
- 👤 Anthony N. Naglieri
- 👤 Nabil Rizkalla
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:16
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/54; C07C51/56
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
69 words
A process for the preparation of an anhydride of a monocarboxylic acid which comprises reacting carbon monoxide and an alkyl or aryl carboxylic acid ester or an alkyl or aryl ether under substantially anhydrous conditions at elevated temperature and superatmospheric pressure in the presence of a halide which is an iodide or a bromide and a catalyst comprising nickel and chromium and in the presence of a tin promoter.
Claim 2
Dependent Claim
69 words
A process for the preparation of an anhydride of a monocarboxylic acid which comprises reacting carbon monoxide and an alkyl or aryl carboxylic acid ester or an alkyl or aryl ether under substantially anhydrous conditions at elevated temperature and superatmospheric pressure in the presence of a halide which is an iodide or a bromide and a catalyst comprising nickel and chromium and in the presence of a tin promoter.
Claim 3
Dependent Claim
33 words
A process as defined in claim 1, wherein the anhydride is a lower alkanoic anhydride, the carboxylic acid ester is a lower alkyl lower alkanoate and the ether is a lower alkyl ether.
Claim 4
Dependent Claim
26 words
A process as defined in claim 1, wherein the anhydride is acetic anhydride, the carboxylic acid ester is methyl acetate and the ether is dimethyl ether.
Claim 5
Dependent Claim
23 words
A process as defined in claim 1, wherein the reaction is carried out under a carbon monoxide partial pressure up to 1000 psi.
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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) | 1980-01-11 | 1980-07-12 | 1981-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-11 | 1984-07-12 | 1985-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-11 | 1988-07-12 | 1989-01-11 | $7700.00 | Window Closed / Lapsed |