# Patent

## Title
Process for 1-chloro-3,3,3-trifluoropropene from trifluoropropene

## Abstract

The present invention provides routes for making 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) from commercially available raw materials. More specifically, this invention provides several routes for forming HCFO-1233zd from 3,3,3-trifluoropropene (FC-1234zf).

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application claims domestic priority from commonly owned U.S. Provisional Application Ser. No. 61/863,735 filed 8 Aug. 2013, the disclosure of which is hereby incorporated herein by reference.


FIELD OF THE INVENTION
The present invention provides routes for making 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) from commercially available raw materials. More specifically, this invention provides routes for HCFO-1233zd from commercially available 3,3,3-trifluoropropene (FC-1234zf).
BACKGROUND OF THE INVENTION
Trans 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) can be used for many applications including use as a refrigerant, blowing agent, solvent, cleaning agent and monomer for polymer compounds. The compounds of the present invention are part of a continued search for the next generation low global warming potential materials with low environmental impact.
Many methods are known in the art for making HCFO-1233zd (trans), most of them using three carbon starting materials which are obtained via multiple steps. For example, U.S. Pat. Nos. 5,777,184 and 6,472,573 describe the preparation of CF3CH═CHCl from CCl3CH2CHCl2 (240fa) with HF in the presence of a catalyst. Treatment of CF3CH2CF2H (245fa) and HCl at 280° C. with chromium catalyst is reported to give 1233zd (trans and cis), see EP 2327680. Reaction of CF3CH═CH2 with chlorine and HF affords 1233zd as one of the products; see WO 2008/54782 A1.
All of the above processes involve three carbon starting materials which in turn are made in multiple steps and thus there is a need to develop cost effective routes which utilize commercially available raw materials. The present invention addresses this issue by utilizing 3,3,3-trifluoropropene (FC-1234zf).
SUMMARY OF THE INVENTION
The present invention describes the preparation of HCFO-1233zd from commercially available 3,3,3-trifluoropropene (FC-1234zf). The compound 3,3,3-tri-fluoropropene can be purchased from a number of vendors or it can be easily prepared via well-known synthetic routes.
The compound 3,3,3-trifluoropropene can be converted to CF3CH═CHCl via three different routes, as follows:
First Route:
In a first method, CF3CH═CH2 is converted directly to HCFO-1233zd in a single step via oxychlorination with HCl, O2 and a supported CuCl2 catalyst.

CF3CH═CH2→CF3CH═CHCl (HCFO-1233zd)

Modifications of the oxychlorination reaction using copper chloride, other copper salts, with rare earth salts or halides can be made to optimize the reaction. See, J. Chem. Education, 1986, 63, 1056-1058 and U.S. Pat. No. 4,025,461.
Reaction conditions, especially the temperature of the reaction, can be adjusted to provide the desired chlorine substituted rather than the unwanted addition product. Typically, the reaction is done by passing a vapor mixture of the olefin, oxygen and HCl over a supported copper catalyst at an elevated temperature, e.g., from 400° to 500° C. as shown in Equation (1) below:




Second Route:

In a second method, 3,3,3-trifluoropropene is reacted with XCl (X═Br, I, OR), such that X is added across the double to afford CF3CHXCH2Cl which is then converted to CF3CH═CHCl via elimination of HX, as shown below in Equation (2):

CF3CH═CH2+XCl→CF3CHXCH2Cl→CF3CH═CHCl+HX  (2)

The by-product formed is CF3CHClCH2X which can be recycled as starting material after dechlorinating with Zn as shown below:

CF3CHClCH2X+Zn→CF3CH═CH2+ZnXCl

Third Route:

A third method involves addition of hydrogen to 3,3,3-trifluoropropene to afford CF3CH2CH3, which is then chlorinated and dehydrochlorinated to give 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) as depicted below in Equations (3), (4) and (5):

CF3CH═CH2+H2→CF3CH2CH3  (3)

CF3CH2CH3+2Cl2→CF3CH2CHCl2+2HCl  (4)

CF3CH2CHCl2→CF3CH═CHCl+HCl  (5)

In the reaction of Equation (4), CF3CH2CCl3 can also be produced at times which can be converted to 1233zd as shown below:

CF3CH2CCl3→CF3CH═CCCl2+HCl  (6)

CF3CH═CCl2+H2→CF3CH2CHCl2  (7)

CF3CH2CHCCl2→CF3CH═CHCl+HCl  (8)

The process involves dehydrochlorination, hydrogenation and subsequent elimination of HCl as depicted in Equations (6), (7), and (8), respectively.
It should be appreciated by those persons having ordinary skill in the art(s) to which the present invention relates that any of the features described herein in respect of any particular aspect and/or embodiment of the present invention can be combined with one or more of any of the other features of any other aspects and/or embodiments of the present invention described herein, with modifications as appropriate to ensure compatibility of the combinations. Such combinations are considered to be part of the present invention contemplated by this disclosure.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein.


DETAILED DESCRIPTION OF THE INVENTION
The present invention provides routes for making 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) from commercially available raw materials. More specifically, this invention provides several routes for forming HCFO-1233zd from 3,3,3-trifluoropropene (FC-1234zf).
Accordingly, one embodiment of the invention is directed to a process for the formation of 1-chloro-3,3,3-trifluoropropene from 3,3,3-trifluoropropene (FC-1234zf), selected from the group of reactions consisting of:

    
    
        (a) the direct conversion of 3,3,3-trifluoropropene into CF3CH═CHCl via an oxychlorination reaction;
        (b) the reaction of 3,3,3-trifluoropropene with XCl (wherein X═Br, I, OR), whereby X is added across the double to afford CF3CHXCH2Cl which is then converted to CF3CH═CHCl by an HX elimination reaction;
        (c) the reaction of 3,3,3-trifluoropropene with hydrogen to afford CF3CH2CH3, which is then chlorinated and dehydrochlorinated to give 1-chloro-3,3,3-trifluoropropene; and
        (d) combinations of two or more of these reactions.
    
    


In certain embodiments, the oxychlorination reaction comprises the reaction of oxygen and hydrogen chloride with the propene, in the vapor phase over a supported catalyst.
In certain embodiments, the supported catalyst is selected from the group consisting of copper chloride salts, rare earth salts, and equivalents thereof.
In certain embodiments, the catalyst comprises CuCl2.
In certain embodiments, the catalyst comprises CuCO3/CeO2.
In certain embodiments, the support of the catalyst is selected from the group consisting of carbon, alumina, and equivalents thereof.
In certain embodiments, the reaction temperature of the oxychlorination reaction ranges from 400° to 550° C.
In certain embodiments, the group X in XCl, is selected from the group consisting of Br, I, and OR, wherein R is a C1 to C6 carbon group.
In certain embodiments, the R group in OR, is selected from methyl, ethyl, propyl, butyl, heptyl, and hexyl.
In certain embodiments, XCl comprises BrCl.
In certain embodiments, XCl comprises ICl.
In certain embodiments, XCl comprises ROCl.
In certain embodiments, CF3CHXCH2Cl comprises CF3CHICH2Cl.
In certain embodiments, the chlorination reaction of CF3CH2CH3 generates a product intermediate comprising CF3CH2CHCl2.
In certain embodiments, the dehydrochlorination reaction of CF3CH2CHCl2 is conducted in the vapor phase at about 400° C. to yield HCFO-1233zd.
In certain embodiments, the ratio of trans to cis HCFO-1233zd is 90:10.
Another embodiment of the invention is directed to a method for producing 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) from 3,3,3-trifluoropropene (FC-1234zf) comprising the step of;
(a) directly converting FC-1234zf directly into HCFO-1233zd by passing a mixture of FC-1234zf, oxygen and hydrogen chloride over an oxychlorination catalyst at a time and temperature sufficient for the conversion.
In certain embodiments, the catalyst is selected from the group consisting of copper chloride salts, rare earth salts, and equivalents thereof.
In certain embodiments, the catalyst comprises CuCl2.
In certain embodiments, the catalyst comprises CuCO3/CeO2.
In certain embodiments, the catalyst comprises a supported catalyst and the support is selected from the group consisting of carbon, alumina, and equivalents thereof.
In certain embodiments, the reaction temperature of the oxychlorination reaction ranges from 400° to 550° C.
Yet another embodiment of the invention is directed to a process for producing 1-chloro-3,3,3-trilfuoroproene (HCFO-1233zd) from 3,3,3-tri-fluoropropene (FC-1234zf) comprising the steps of:
(a) addition of XCl to 3,3,3-trifluorpropene to form CF3CHXCH2Cl; and
(b) elimination of HX from CF3CHXCH2Cl to form HCFO-1233zd.
In certain embodiments, the X group in XCl is selected from the group consisting of Br, I, and OR, wherein R is a C1 to C6 carbon group.
In certain embodiments, the R group in ROCl is selected from methyl, ethyl, propyl, butyl, heptyl, and hexyl.
In certain embodiments, XCl comprises BrCl.
In certain embodiments, XCl comprises ICl.
In certain embodiments, XCl comprises ROCl.
In certain embodiments, CF3CHXCH2Cl comprises CF3CHICH2Cl.
In certain embodiments, the chlorination reaction of CF3CH2CH3 generates a product intermediate comprising CF3CH2CHCl2.
In certain embodiments, the dehydrochlorination reaction of CF3CH2CHCl2 is conducted in the vapor phase at about 400° C. to yield HCFO-1233zd.
In certain embodiments, the ratio of trans to cis HCFO-1233zd is 90:10.
Yet another embodiment of the invention is directed to a process for producing 1-chloro-3,3,3-trilfuoroproene (HCFO-1233zd) from 3,3,3-trifluoropropene (FC-1234zf) comprising the steps of:
(a) hydrogenation of 3,3,3-trifluorpropene to form CF3CH2CH3;
(b) chlorination of CF3CH2CH3 to form CF3CH2CHCl2 and
(c) dehydrochlorination of CF3CH2CHCl2 to form HCFO-1233zd.
In general, it is possible that certain reactions employed herein can be carried out in the liquid phase or in the gas phase, or in a combination of gas and liquid phases, and it is contemplated that the reactions can be carried out batch wise, continuously, or by a combination of these.
Preferably the reactor vessel is comprised of materials which are resistant to corrosion as Hastelloy, Inconel, Monel and/or fluoropolymers linings.
In certain embodiments the reactor vessel contains catalyst, for example a fixed or fluid catalyst bed, packed with a suitable catalyst, with suitable means to ensure that the reaction mixture is maintained with the desired reaction temperature range.
In general it is also contemplated that a wide variety of reaction pressures may be used for the reactions, depending again on relevant factors such as the specific catalyst being used. The reaction pressure can be, for example, superatmospheric, atmospheric or under vacuum and in certain preferred embodiments is from about 1 to about 200 psia, and in certain embodiments from about 1 to about 120 psia.
In certain embodiments, an inert diluent gas, such as nitrogen, may be used in combination with the other reactor feed(s).
It is contemplated that the amount of catalyst use will vary depending on the particular parameters present in each embodiment.
EXAMPLES
The following examples provide additional details regarding various embodiments of the present invention. However, the present invention is not limited to the following examples.
Example 1
Conversion of CF3CH═CH2 Directly to CF3CH═CHCl Via Oxychlorination
Into an Inconel tube reactor (0.5 inch×14 inch) was loaded 25 cc of copper chloride supported on alumina (7 to 10 g CuCl2/100 g of impregnated support). Then a mixture of 3,3,3-trifluoropropene, oxygen and hydrogen chloride in the ratio 1:0.5:2, respectively, was passed over the heated supported catalyst with a contact time of from 5 to 20 sec in the temperature range of from 450° to 550° C. The yield of CF3CH═CHCl ranged from 20% to 50%. The main by-product was CF3CHClCH2Cl.
Example 2
The reaction was conducted in the same way as described in Example 1 except the catalyst used was CuCO3/CeO2 (equimolar; 7 to 10 g/100 g gamma alumina support) calcined at 900° C. for 1 hour. The conversion of CF3CH═CH2 ranged from 50% to 75% with 30% to 60% yield of CF3CH═CHCl in the product mixture for 3 runs at 450°, 500°, 550° C., respectively. Note that this reaction can be conducted in a continuous manner.
Example 3
Preparation of CF3CHICH2Cl
Into a 250 mL stainless steel autoclave containing 0.05 mol of ICl and 100 mL dichloromethane at −20° C. was condensed/added 0.05 mol of 3,3,3-trifluoropropene. The autoclave was then brought to 0° C. and stirred for 48 h. The product was washed with 5% aq. NaHSO3 solution and then by water (2×25 mL) to afford the product CF3CHICH2Cl (40%) along with CF3CHClCH2I; CF3CHICH2Cl was separated via distillation and used for the next step.
Example 4
Conversion of CF3CHICH2Cl to CF3CH═CHCl
A stainless steel tube reactor (0.5 inch×12 inch) was loaded with 30 cc of fluorinated chromia (Cr2O3) catalyst and heated to 200° C. with a nitrogen purge. Then the nitrogen flow was stopped and CF3CHICH2Cl was added (1 to 2 mL/min), vaporized and passed over the heated catalyst to afford a mixture of CF3CH═CHCl (60%) and CF3CCl ═CH2 (40%). The CF3CH═CHCl thus formed was separated via distillation.
Example 5
Preparation of CF3CH═CHCl Via Hydrogenation, Chlorination and Dehydrochlorination of CF3CH═CH2 
Step A—Hydrogenation:
Into a 350 mL stainless steel autoclave was added 1 g of hydrogenation catalyst (about 2% Pd on C), and 50 mL methanol under a nitrogen purge. The autoclave was sealed, cooled to −20° C. and evacuated to remove excess nitrogen. Next was added 0.10 mol of CF3CH═CH2. Then autoclave was brought to about 0° C. and slowly charged with 0.01 mol H2; the reaction was monitored by the drop in pressure over time. The reaction was stopped once there was no more change in pressure and the product, mainly CF3CH2CH3, was distilled off from the reactor to afford (0.08 mol, 80% yield).
Step B—Chlorination:
Chlorination of CF3CH2CH3 to CF3CH2CHCl2 was accomplished by passing a mixture of CF3CH2CH3 and Cl2 (about 1:2 ratio) through a heated (375° to 425° C.) tube reactor containing activated carbon. The conditions could be optimized to give mainly CF3CH2CHCl2. The by-products formed were CF3CH2CCl3 and CF3CH2CH2Cl.
Step C—Dehydrochlorination of CF3CH2CHCl2:
Vaporized CF3CH2CHCl2 (about 30 sccm) was passed over a heated fluorinated Cr2O3 catalyst column (25 cc) in a stainless steel tube reactor (0.5 inch×14 inch) placed in a furnace (400° C.); the contact time was about 25 to 30 sec. Under these conditions 80% product in the exit stream was CF3CH═CHCl (90% trans and 10% cis). In this manner 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) could be prepared continuously.
As used herein, the singular forms “a”, “an” and “the” include plural unless the context clearly dictates otherwise. Moreover, when an amount, concentration, or other value or parameter is given as either a range, preferred range, or a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the scope of the invention be limited to the specific values recited when defining a range.
It should be understood that the foregoing description is only illustrative of the present invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances that fall within the scope of the appended claims.

## Claims

1. A method for the formation of 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) from 3,3,3-trifluoropropene (FC-1234zf) comprising the direct conversion of 3,3,3-trifluoropropene into CF3CH═CHCl by reaction with oxygen and hydrogen chloride.

2. The method of claim 1, wherein the reaction is run in a continuous manner.

3. A method for the formation of 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) from 3,3,3-trifluoropropene (FC-1234zf), selected from the group of reactions consisting of:
(a) the reaction of 3,3,3-trifluoropropene with XCl, whereby XCl is added across the double to afford CF3CHXCH2Cl which is then converted to CF3CH═CHCl by an HX elimination reaction;
(b) the reaction of 3,3,3-trifluoropropene with hydrogen to afford CF3CH2CH3, which is then chlorinated and dehydrochlorinated to give 1-chloro-3,3,3-trifluoropropene; and
(c) combinations of these reactions.

4. The method of claim 3, wherein the oxychlorination reaction comprises the reaction of oxygen and hydrogen chloride with the propene, in the vapor phase over a supported catalyst.

5. The method of claim 4 where oxygen to hydrogen chloride ratio is 0.5 to 1.

6. The method of claim 4, wherein the supported catalyst is selected from the group consisting of copper chloride salts, rare earth salts, and equivalents thereof.

7. The method of claim 5, wherein the catalyst comprises CuCl2.

8. The method of claim 5, wherein the catalyst comprises CuCO3/CeO2.

9. The method of claim 4, wherein the support of the catalyst is selected from the group consisting of carbon, alumina, and equivalents thereof.

10. The method of claim 4, wherein the reaction temperature of the oxychlorination reaction ranges from 400° to 550° C.

11. The method of claim 3, wherein X in XCl is selected from the group consisting of Br, I, and OR, wherein R is a C1 to C6 carbon group.

12. The method of claim 11, wherein R is selected from methyl, ethyl, propyl, butyl, heptyl, and hexyl.

13. The method of claim 11, wherein XCl comprises BrCl.

14. The method of claim 11, wherein XCl comprises ICl.

15. The method of claim 11, wherein XCl comprises ROCl.

16. The method of claim 11, wherein CF3CHXCH2Cl comprises CF3CHICH2Cl.

17. The method of claim 3, wherein the chlorination reaction of CF3CH2CH3 generates a product intermediate comprising CF3CH2CHCl2.

18. The method of claim 17, wherein dehydrochlorination reaction of CF3CH2CHCl2 is conducted in the vapor phase at about 400° C. to yield HCFO-1233zd.

19. The method of claim 18, wherein the ratio of trans to cis HCFO-1233zd is 90:10.

20. A process for producing 1-chloro-3,3,3-trilfuoroproene (HCFO-1233zd) from 3,3,3-tri-fluoropropene (FC-1234zf) comprising the steps of:
(a) addition of XCl to 3,3,3-trifluorpropene to form CF3CHXCH2Cl; and
(b) elimination of HX from CF3CHXCH2Cl to form HCFO-1233zd.

21. A process for producing 1-chloro-3,3,3-trilfuoroproene (HCFO-1233zd) from 3,3,3-trifluoropropene (FC-1234zf) comprising the steps of:
(a) hydrogenation of 3,3,3-trifluorpropene to form CF3CH2CH3;
(b) chlorination of CF3CH2CH3 to form CF3CH2CHCl2 and
(c) dehydrochlorination of CF3CH2CHCl2 to form HCFO-1233zd.