US4206126A
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Preparation of cyclic α,β-unsaturated ethers
Assignee: BASF SE
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Filing: 1979-01-10
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Granted: 1980-06-03
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Expires: 1999-01-10
Abstract
Abstract Cyclic α,β-unsaturated ethers are prepared by isomerizing the corresponding β,γ-unsaturated ethers at from 50° to 250° C. in the presence of an iron carbonyl as the catalyst, and of a base.
Inventors
- 👤 Walter Rebafka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:01
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/02; C07D307/26; C07D307/28; C07D309/00; C07D309/16; C07D309/18
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
67 words
A process for the preparation of a cyclic alpha, beta-unsaturated ether by isomerizing a corresponding substituted or unsubstituted 2,5-dihydrofuran or a substituted or unsubstituted 5,6-dihydropyran with iron pentacarbonyl as the catalyst, wherein the isomerization is carried out at from 50° to 250° C. in the presence of a base selected from the group consisting of an alkali metal hydroxide, alkaline earth metal hydroxide and an organic amine.
Claim 2
Dependent Claim
67 words
A process for the preparation of a cyclic alpha, beta-unsaturated ether by isomerizing a corresponding substituted or unsubstituted 2,5-dihydrofuran or a substituted or unsubstituted 5,6-dihydropyran with iron pentacarbonyl as the catalyst, wherein the isomerization is carried out at from 50° to 250° C. in the presence of a base selected from the group consisting of an alkali metal hydroxide, alkaline earth metal hydroxide and an organic amine.
Claim 3
Dependent Claim
34 words
The process of claim 1, wherein the iron penta carbonyl is used in an amount of from 0.05 to 5% by weight, preferably from 0.5 to 2% by weight, based on the starting material.
Claim 4
Dependent Claim
32 words
The process of claim 1, wherein the base is used in an amount of from 0.01 to 5% by weight, preferably from 0.5 to 2% by weight, based on the starting material.
Claim 5
Dependent Claim
20 words
The process of claim 1, wherein an alkali metal hydroxide or alkaline earth metal hydroxide is used as the base.
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) | 1983-06-03 | 1983-12-03 | 1984-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-03 | 1987-12-03 | 1988-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-03 | 1991-12-03 | 1992-06-03 | $7700.00 | Window Closed / Lapsed |