US4110407A
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Preparation of 1-chloro-2-trifluoromethyl-3,3,3-trifluoropropene from isobutane
Assignee: Honeywell International Inc
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Filing: 1977-11-21
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Granted: 1978-08-29
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Expires: 1997-11-21
Abstract
Abstract Isobutane is catalytically converted to 1-chloro-2-trifluoromethyl-3,3,3-trifluoropropene [(CF3)2C = CHCl] in a dehydro/chlorofluorination reaction zone by passing a mixture of anhydrous hydrogen fluoride, chlorine and the isobutane over a chromium oxide or metal fluoride dehydro/chlorofluorination catalyst. Alternatively, the isobutane feed is first prechlorinated, and the mixture of prechlorination fed for conversion to the desired (CF3)2C = CHCl, to a downstream fluorination reactor charged with the dehydro/chlorofluorination catalyst.
Inventors
- 👤 Louis G. Anello
- 👤 Richard F. Sweeney
- 👤 Bernard Sukornick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:21
CPC Classifications
C; C07; C07C; C07C21/00; C07C21/02; C07C21/18; C07C17/00; C07C17/013; C07C17/04
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
76 words
A process for the preparation of 1-chloro-2-trifluoromethyl-3,3,3-trifluoropropene in high yield, comprising prechlorinating an isobutane feed to such extent that the product of chlorination attains an average chlorine content of at least 4 chlorine atoms per molecule, and thence fluorinating said product of chlorination in a reaction zone by passing said product, together with hydrogen fluoride and chlorine, over a dehydro/chlorofluorination catalyst selected from the group consisting of a chromium oxide and a metal fluoride dehydro/chlorofluorination catalyst.
Claim 2
Dependent Claim
76 words
A process for the preparation of 1-chloro-2-trifluoromethyl-3,3,3-trifluoropropene in high yield, comprising prechlorinating an isobutane feed to such extent that the product of chlorination attains an average chlorine content of at least 4 chlorine atoms per molecule, and thence fluorinating said product of chlorination in a reaction zone by passing said product, together with hydrogen fluoride and chlorine, over a dehydro/chlorofluorination catalyst selected from the group consisting of a chromium oxide and a metal fluoride dehydro/chlorofluorination catalyst.
Claim 3
Dependent Claim
16 words
The process as defined by claim 1, wherein the prechlorination is effected in a single step.
Claim 4
Dependent Claim
17 words
The process as defined by claim 1, wherein the prechlorination is effected in a plurality of steps.
Claim 5
Dependent Claim
23 words
The process as defined by claim 1, wherein the chlorine/isobutane mole ratio in the prechlorination feed ranges from between about 2:1 to 12:1.
Claim 6
Dependent Claim
23 words
The process as defined by claim 1, wherein an inert gas stream is utilized to sweep the prechlorination reactants through the prechlorination zone.
Claim 7
Dependent Claim
68 words
The process as defined by claim 3, wherein the prechlorination is effected in two prechlorination reaction zones, with the reactant contact time in the first reaction zone ranging from between about 0.01 to 1 second, and the reactant contact time in the second reaction zone ranging from between about 1 and 50 seconds, the temperature in said second reaction zone being maintained at about 300° to 400° C.
Claim 8
Dependent Claim
58 words
The process as defined by claim 1, wherein the fluorination reaction zone is maintained at a temperature of from about 300° to 500° C., the reactant contact time in the fluorination reaction zone ranges from between about 1 and 50 seconds, and the hydrogen fluoride/organic mole ratio in said fluorination reaction zone ranges from between 2:1 to 20:1.
Claim 9
Dependent Claim
19 words
The process as defined by claim 1, wherein the product of prechlorination comprises a mixture of chloroisobutanes and chloroisobutenes.
Claim 10
Dependent Claim
27 words
The process as defined by claim 7, wherein the dehydro/chlorofluorination catalyst is selected from the group consisting of a polyvalent metal fluoride and a transition metal fluoride.
Claim 11
Dependent Claim
13 words
The process as defined by claim 7, wherein the catalyst is chromium oxide.
Claim 12
Dependent Claim
32 words
The process as defined by claim 1 wherein the dehydro/chlorofluorination catalyst is borne by a support selected from the group consisting of carbon, alumina, calcium fluoride, magnesium fluoride and sodium magnesium fluoride.
Claim 13
Dependent Claim
18 words
The process as defined by claim 10, wherein the chromium oxide catalyst further includes a metal salt modifier.
Claim 14
Dependent Claim
24 words
The process as defined by claim 10, wherein the chromium oxide catalyst further includes a metal oxide promoter, said metal being other than chromium.
Claim 15
Dependent Claim
17 words
The process as defined by claim 10, wherein the chromium oxide catalyst is dehydrated chromium oxide hydrate.
Claim 16
Dependent Claim
41 words
The process as defined by claim 1, wherein the catalyst is a metal fluoride selected from the group consisting of AlF 3 , FeF 3 , KMgF, V 2 OF 4 , ZrF 4 , CoF 2 and CrF 3 .
Claim 17
Dependent Claim
49 words
The process as defined by claim 13, wherein the promoter is selected from the group consisting of NiO, Fe 2 O 3 , ZnO, Al 2 O 3 , SrO 2 , Al 2 O 3 -SrO 2 , TiO 2 and AlF 3 -Al 2 O 3 .
Claim 18
Dependent Claim
25 words
The process as defined by claim 1, wherein the product of prechlorination is condensed and purified prior to passing same over the metal dehydro/chlorofluorination catalyst.
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) | 1981-08-28 | 1982-02-27 | 1982-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-28 | 1986-02-27 | 1986-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-28 | 1990-02-27 | 1990-08-29 | $7700.00 | Window Closed / Lapsed |