Patent US4000023A successfully refreshed from Google Patents.
US4124600A
Expired / Lapsed
US
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Preparation of tetrahydrofuran
Assignee: EIDP Inc
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Filing: 1975-05-28
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Granted: 1978-11-07
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Expires: 1995-05-28
Abstract
Abstract Tetrahydrofuran is prepared by the vapor phase reaction of a compound selected from 1,4-butanediol, monoesters of 1,4-butanediol, diesters of 1,4-butanediol and mixtures thereof in the presence of water and an acid catalyst wherein the catalyst is selected from phosphoric acid on a suitable support and eta alumina at a temperature of from about 200° to about 325° C followed by the recovery of the tetrahydrofuran by distillation.
Inventors
- 👤 Colie L. Jenkins, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:58
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/02; C07D307/04; C07D307/06; C07D307/08
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
129 words
A process for the preparation of tetrahydrofuran comprising contacting the monoester of 1,4-butanediol of the formula ##STR2## where R and R' are selected from hydrogen and ##STR3## and at least one of R or R' is ##STR4## where R 2 is hydrogen or an alkyl radical of 1 to 5 carbon atoms or mixtures of said monoester with a diester of the above formula in the vapor phase in the presence of water or steam with a catalytic amount of a catalyst selected from phosphoric acid on a support material and eta alumina at a temperature of from about 200° to about 325° C, wherein the monoester or said mixtures are contacted with the catalyst from 1 second to 1 minute, and recovering the tetrahydrofuran from the reaction mixture.
Claim 2
Dependent Claim
129 words
A process for the preparation of tetrahydrofuran comprising contacting the monoester of 1,4-butanediol of the formula ##STR2## where R and R' are selected from hydrogen and ##STR3## and at least one of R or R' is ##STR4## where R 2 is hydrogen or an alkyl radical of 1 to 5 carbon atoms or mixtures of said monoester with a diester of the above formula in the vapor phase in the presence of water or steam with a catalytic amount of a catalyst selected from phosphoric acid on a support material and eta alumina at a temperature of from about 200° to about 325° C, wherein the monoester or said mixtures are contacted with the catalyst from 1 second to 1 minute, and recovering the tetrahydrofuran from the reaction mixture.
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein the catalyst is phosphoric acid on a support material.
Claim 4
Dependent Claim
11 words
The process of claim 1 wherein the catalyst is eta alumina.
Claim 5
Dependent Claim
22 words
The process of claim 1 wherein R is hydrogen and R 2 is an alkyl radical of 1 to 5 carbon atoms.
Claim 6
Dependent Claim
15 words
The process of claim 4 wherein the catalyst is phorphoric acid on a support material.
Claim 7
Dependent Claim
12 words
The process of claim 4 wherein the acid catalyst is eta alumina.
Claim 8
Dependent Claim
15 words
The process of claim 1 wherein mixtures of the monoester and the diester are contacted.
Claim 9
Dependent Claim
11 words
The process of claim 7 wherein the catalyst is eta alumina.
Claim 10
Dependent Claim
15 words
The process of claim 7 wherein the catalyst is phosphoric acid on a support material.
Claim 11
Dependent Claim
10 words
The process of claim 1 wherein the monoester is contacted.
Claim 12
Dependent Claim
11 words
The process of claim 10 wherein the catalyst is eta alumina.
Claim 13
Dependent Claim
15 words
The process of claim 11 wherein the catalyst is phosphoric acid on a support material.
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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) | 1981-11-06 | 1982-05-08 | 1982-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-06 | 1986-05-08 | 1986-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-06 | 1990-05-08 | 1990-11-07 | $7700.00 | Window Closed / Lapsed |