WO2016009214A1

WO2016009214A1 - Process for the preparation of 1,1,2,3-tetrachloropropene (1230xa), 1,2,3,3-tetrachloropropene (1230xd) or a mixture thereof

Info

Publication number: WO2016009214A1
Application number: PCT/GB2015/052061
Authority: WO
Inventors: Andrew Paul Sharratt; Emma Jane HODGSON; John Charles Mccarthy; Maxine DORAN
Original assignee: Mexichem UK Ltd; Mexichem Amanco Holding SA de CV
Current assignee: Mexichem UK Ltd; Orbia Advance Corp SAB de CV
Priority date: 2014-07-17
Filing date: 2015-07-16
Publication date: 2016-01-21
Anticipated expiration: 2017-01-17
Also published as: GB2528310A8; GB2528310A; GB201412743D0

Abstract

The present invention relates to a process for the preparation of 1,1,2,3- tetrachloropropene (1230xa), 1,2,3,3-tetrachloropropene (1230xd) or a mixture thereof. In a further aspect the invention relates to a process for the preparation of a composition comprising 1,1,2,3-tetrachloropropene (1230xa), 1,2,3,3-tetrachloropropene (1230xd) or a mixture thereof.

Description

PROCESS FOR THE PREPARATION OF 1 ,1 ,2,3-TETRACHLOROPROPENE (1230XA), 1 ,2,3,3-TETRACHLOROPROPENE

(1230XD) OR A MIXTURE THEREOF

The invention relates to a process for the preparation of 1 ,1 ,2,3-tetrachloropropene 1 ,2,3,3-tetrachloropropene or a mixture thereof. In a further aspect the invention relates to a process for the preparation of a composition comprising 1 ,1 ,2,3-tetrachloropropene, 1 ,2,3,3-tetrachloropropene or a mixture thereof.

1 ,1 ,2,3-tetrachloropropene is also known as HCC-1230xa or 1230xa. Hereinafter, unless otherwise stated, 1 ,1 ,2,3-tetrachloropropene will be referred to as 1230xa.

1 ,2,3,3-tetrachloropropene is also known as HCC-1230xd or 1230xd. 1 ,2,3,3- tetrachloropropene can exist as the E or Z isomer. Hereinafter, unless otherwise stated, 1 ,2,3,3-tetrachloropropene will be referred to as 1230xd when referring to the compound in general or to a mixture of the isomers or 1230xd(E) or 1230xd(Z) when referring to the specific isomer.

1230xa and 1230xd are useful as synthetic intermediates from which a range of pharmaceutical and agrochemicals as well as various hydrofluoroolefins, such as 2,3,3,3-tetrafluoropropene and 1 ,3,3,3-tetrafluoropropene can be produced.

2,3,3,3-tetrafluoropropene is also known as HCF-1234yf, R-1234yf or 1234yf. Hereinafter, unless otherwise stated 2,3,3,3-tetrafluoropropene will be referred to as 1234yf. Hydrofluorocarbon (HFC) products are widely used in many applications, including refrigeration, air conditioning, foam expansion, and as propellants for aerosol products including medical aerosol devices. Although HFC's have proven to be more climate friendly than chlorofluorocarbons and hydrochlorofluorocarbon products that they have replaced, it has been discovered that they exhibit an appreciable global warming potential.

The search for alternatives to current fluorocarbon products has led to the emergence of hydrofluoroolefin (HFO) products. Relative to their predecessors, HFO's are expected to exert less impact on the atmosphere in the form of a lesser, or no, detrimental impact on the ozone layer and their lower global warming potential (GWP) as compared to HFC's. Advantageously, HFO's also exhibit low flammability and low toxicity. 1234yf has been identified as a candidate alternative refrigerant to replace 1 ,1 , 1 ,2- tetrafluoroethane (R-134a, hereinafter referred to as 134a) in certain applications, notably mobile air conditioning or heat pumping applications. Its GWP is about 4. Of the routes to 1234yf, two have emerged as being commercially significant.

1) Hexafluoropropene (HFP)→ 1 ,1 , 1 ,2,3,3-hexaf!uoropropane (236ea)→ 1 , 1 , ,2,3- pentafluoropropene (1225ye)→ 1 , 1 , 1 ,2,3-pentafluoropropane (245eb)→ 1234yf 2) 1230xa → 2-chloro-3,3,3-trif!uoro-1-propene (1233xf) → 1 , 1 , 1 ,2-tetrafluoro-2- chloropropane (244bb)→ 1234yf

The route starting from HFP is relatively straight forward, with each step being clean and high yielding. However, the availability and cost of HFP restricts the commercial viability of this route.

The route starting from 1230xa is also relatively straight forward and may be considered to be the favoured route for commercial scale preparation. 1234yf can also be prepared from 1230xd.

1) 1230xd 1 ,2,3,3,3-pentachloro-1-propene 1 , 1 , 1 ,2,3-pentachloropropane 2- chloro-3,3,3-trifluoro-1-propene (1233xf) -» 1 ,1 , 1 ,2-tetrafluoro-2-chloropropane (244bb) → 1234yf

However, species such as 1230xa and 1230xd are considered difficult to synthesize with their production processes often requiring many sequential chlorination and dehydrochlorination steps with low yields, and/or the handling of toxic and/or expensive reagents, and/or the use of extreme conditions, and/or the production of toxic by- products, see for example CN 101955414, WO2011/065574, US2009/0030249 and WO2012/166393.

It is therefore desirable to provide a new process for the preparation of 1230xa, 1230xd or mixtures thereof which addresses one or more of the disadvantages of the known processes. The present invention seeks to address one or more of these issues. The listing or discussion of a prior-published document in this specification should not necessarily be taken as an acknowledgement that the document is part of the state of the art or is common general knowledge. The present invention provides a process for the production of 1230xa, 1230xd or mixtures thereof by using 1 ,1 ,3-trichloroacetone (TCA) as the starting material. TCA has a number of synthetic uses and is produced commercially by a number of companies including Wacker Chimie of Germany. The present invention provides a process for the production of 1230xa, 1230xd or mixtures thereof comprising reacting TCA with a nucleophilic chlorinating agent. Nucleophilic chlorinating agents that can be used in the present invention include, but are not limited to phosphorous pentachloride (PCIs), thionyl chloride and triarylphosphine dichlorides. Phosphorous pentachloride is preferred because it is readily available and has many existing applications.

The present invention also provides a process for the production of a composition comprising 1230xa, 1230xd or a mixture thereof by the chlorination of TCA with a nucleophilic chlorinating agent e.g. PCI5.

lldUxd (t l)

If it is considered desirable to separate the 1230xa and 1230xd isomers this can be achieved by any known separation method for example distillation (at, for example, super or sub atmospheric pressure), solvent extraction and/or crystallisation.

Without wanting to be bound by theory, it is thought that TCA reacts with the nucleophilic chlorinating agent e.g. PCI5, to initially form 240aa, which then proceeds to lose HCI resulting in the production of 1230xa or 1230xd or a mixture thereof. Chlorinated acetone impurities in the TCA, e.g. 1 ,3-dichloroacetone also react with the nucleophilic chlorinating agent to form chlorinated propanes, e.g. 1 ,2,2,3-tetrachloropropane (250aa), which then lose HCI to form precursors to 1230xa using the indirect sequence illustrated below:

-MCI CiH.G-CG CHG 12 m

C:,HC CC _^ CH_^C

-HCI

In a further aspect, the present invention provides the use of 1230xa prepared from the chlorination of TCA with a nucleophilic chlorinating agent in the preparation of 1234yf.

CI₂C=CCICH₂CI 1230xa

HF

H₂C=CCICF₃ 1233xf

HF

H3C-CCIFCF3 244bb

-HCI

H₂C=CFCF₃ 1234yf

In the present invention the chlorination reaction of TCA may be carried out batch-wise or continuously, preferably continuously. Any suitable apparatus may be used, such as a static mixer, a tubular reactor, a stirred tank reactor or a stirred vapour-liquid disengagement vessel. Preferably, the apparatus is made from one or more materials that are resistant to corrosion, e.g. stainless steels, Hastelloy^®, Inconel^®, glass or glass lined vessels. The product from the chlorination reaction may be subjected to one or more purification steps. The purification may be achieved, for example, by separation of the desired product or reagents by one or more distillation, condensation or phase separation steps and/or by scrubbing with water or aqueous base and drying with e.g. molecular sieves, zeolites or other desiccants. Any unreacted TCA can be recycled to the reactor where it will ultimately be converted to 1230xa, 1230xd or a mixture thereof.

The chlorination reaction typically converts at least about 50% of the starting TCA into 1230xa, 1230xd or a mixture thereof, preferably at least about 75%, for example about 90%.

The chlorination reaction TCA- 230xa, 1230xd or mixtures thereof with a nucleophilic chlorinating agent e.g. PCIs can be carried out in many ways but is typically carried out in the liquid phase. Given the various ways in which the reaction can be performed, for example batch or continuous reaction, a stirred reactor or trickle bed, a wide range of conditions can be employed to affect it. In the liquid phase a temperature of from about - 40 to 200 °C may be used, e.g. from about -25 to about 150 °C. Lower and higher temperatures can be used but at the expense of rate and selectivity i.e. ratio of desired product to by-products. Preferred temperatures for liquid phase chlorination are from about 0 to about 180 °C, e.g. from about 50 to about 150 °C.

If the reaction is performed in the vapour phase the person skilled in the art would appreciate that the reaction may be performed under different conditions to the liquid phase. For example, if the vapour phase reaction is performed at super-atmospheric pressure then higher temperatures would be expected. Conversely, if it was performed at sub-atmospheric pressure similar or even lower temperatures might be expected.

If the reaction is conducted in the liquid phase any suitable solvent may be used or the reaction can be conducted in the absence of solvent, i.e. solvent free. By suitable we mean a solvent in which the reactants dissolve or are miscible in. The solvent should be stable to chlorination and should not react with either the reactants or products within the taught ranges of temperature, pressure etc. If a solvent is present it is preferred that the chlorination reaction is carried out in the absence of water. This means that preferably the solvent is not water or does not comprise water. Suitable solvents include, but are not limited to, chlorohydrocarbons such as methylene chloride, chloroform and the like. In one embodiment, an excess of the TCA feedstock or the 1230xa and/or 1230xd product itself can be used as the solvent.

The chlorination reaction TCA->1230xa, 1230xd or a mixture thereof may be carried out at atmospheric, sub- or super-atmospheric pressure, preferably super-atmospheric pressure. For example, the chlorination may be carried out at a pressure of from about 0 to about 4 MPa (40 bara), such as from about 0.1 to about 3 MPa (1 to 30 bara), e.g. from about 0.1 to about 2 MPa (1 to 20 bara). In a preferred aspect, the TCA used in the process of the present invention is purified before reacting with a nucleophilic chlorinating agent, such as PCI5.

A method for the purification of TCA is described in CN101768066. TCA may be purified using a modified process from CN 101768066, which comprises dissolving the TCA in a solvent that is a combination of a polar solvent and a non-polar solvent in a specified ratio and cooling the solution obtained in order to obtain purified crystals of TCA. In a preferred purification process, the polar solvents are selected from water, methanol, ethanol, n-propanol, isopropanol, methyl acetate or ethyl acetate and the non-polar solvents are selected from petroleum ether, pentanes, such as n-pentane, hexanes, such as n-hexane, cyclohexane, heptanes, such as n-heptane, benzene or toluene and the ratio of polar solvent to non-polar solvent is from 1 :1 to 1 : 10, such as 1 :2 to 1 :5.

The ratio of TCA:nucleophilic chlorinating agent e.g. PCI5 on a molar basis is suitably from about 0.1 :1 to about 40:1 , such as from about 1 : 1 to about 20: 1 , preferably from about 1 :1 to about 10: 1 , e.g. from 1.5: 1 to about 5: 1. In situations where the TCA is used in excess in the reaction the TCA can also perform the role of a reaction solvent.

Preferably the reaction is conducted in the absence of water or any other species that may react with either the TCA, or the nucleophilic chlorinating agents, such as PCI5, or the 1230xa and/or 1230xd product. When operated batchwise, the nucleophilic chlorinating agent, e.g. PCI5, is typically used in an amount relative to the TCA such that the preferred ratios disclosed above are achieved. For continuous operation there should be sufficient nucleophilic chlorinating agent, e.g. PCI5, to allow commercially significant conversion to be achieved across the range of contact times and conditions specified.

In the vapour phase the chlorination reaction is typically conducted for a defined period, for example from 1 to 1000 hours, such as from about 10 to about 500 hours, e.g. from about 20 to about 200 hours. It is preferred that the chlorination reaction is conducted for a period of from about 30 to about 90 hours.

In the liquid phase the chlorination reaction is typically conducted for a defined period, for example from 1 to 1000 hours, such as from about 1 to about 500 hours, e.g. from about 1 to about 20 hours. The chlorination reaction is exothermic. The exotherm that accompanies the reaction can be managed by controlling the rate at which the reaction occurs and removing the heat of reaction. The heat of reaction can be removed by normal means such as applying cooling either internally or externally. Heat can also be removed by allowing the solvent to boil, condense and return to the reactor cold.

The present invention also provides a process for the preparation of 1230xa, 1230xd or mixtures thereof comprising the steps of;

i. adding PCI5 to a solution of TCA;

ii. heating the reaction from about 1 hour to about 1000 hours; and

iii. isolating 1230xa, 1230xd or mixtures thereof from the reaction mixture.

In a further aspect, the present invention provides a process for the preparation of 1230xa, 1230xd, or mixtures thereof which further comprises purifying the TCA before step (i).

The present invention also provides a process for the preparation of 1234yf comprising converting 1230xa to 1234yf, wherein the 1230xa is obtained using the process of the invention. The present invention also provides the use of 1230xa in the preparation of 1234yf, wherein the 1230xa is obtained using the process of the invention. The present invention also provides a process for the preparation of 1234yf comprising: i. converting 1230xa to 1233xf, wherein the 1230xa is obtained using the process of the invention;

ii. converting 1233xf to 244bb; and

iii. converting 244bb to 1234yf.

The present invention also provides a process for preparing 1234yf which comprises a process of the invention and the additional step of converting 1230xa to 1234yf.

The present invention also provides a process for the production of 1230xa, 1230xd or mixtures thereof, in which 240aa is isolated as an intermediate and the 240aa is then converted into 1230xa, 1230xd or a mixture thereof. Those skilled in the art will appreciate that if the 240aa intermediate is isolated the reaction conditions can be adjusted to favour regioselective loss of HCI from the 240aa molecule to favour particular isomers during its onward conversion to 1230xa, 1230xd or a mixture thereof.

The present invention also provides a process for preparing at least one hydrofluoroolefin comprising converting 1230xd to at least one hydrofluoroolefin, such as at least one hydrofluoropropene, e.g. 1234yf, wherein the 1230xd is obtained using the process of the invention.

The present invention also provides the use of 1230xd in the preparation of at least one hydrofluoroolefin, such as at least one hydrofluoropropene, e.g. 1234yf, wherein the 1230xa is obtained using the process of the invention.

The present invention also provides a process as described in Example 2 or Example 3.

Typically in the process of the invention, the nucleophilic chlorinating agent is PCI5.

Typically the process of the invention is conducted in the liquid phase.

Typically the process of the invention is conducted at a temperature of from about 100 °C to about 180 °C.

Preferences and options for a given aspect, feature or parameter of the invention should, unless the context indicates otherwise, be regarded as having been disclosed in combination with any and all preferences and options for all other aspects, features and parameters of the invention.

The invention will now be illustrated by the following non-limiting examples.

Examples

Example 1 - Purification of 1 , 1 ,3-trichloroacetone (TCA) (purchased from Sigma Aldrich) TCA was taken up in either 1 :5 methyl acetate :hexane or 1 :2 ethyl acetate: petroleum ether according to the method published in CN 101768066 and then cooled to -15°C in a bath of glycol/dry CO₂ while stirring. After 2 h of cooling and stirring, the solution was filtered under vacuum through a sintered funnel that had been pre-cooled in the freezer to yield crystals of TCA.

It was found that greater yields of crystals were obtained if the solution was pre-seeded with some TCA crystals.

Upon warming to room temperature the crystals melted and were analysed by GC-MS. The best results were obtained using 1 :2 ethyl acetate: petroleum ether, which increased the TCA purity to 93%.

The results of purification reactions are summarised in Table 1 along with their impurities as determined by GC-MS.

Table 1: Results forTCA purification attempts

Example 2 - Process for the preparation of 1230xa, 1230xd or a mixture thereof from purified 1 ,1 ,3-trichloroacetone (TCA) (85% purity)

A clean, dry, 3-necked round bottomed flask (100 mL) containing a magnetic stirrer bar was loaded with PCIs (40.3 g, 0.19 mol) in a nitrogen-purged glovebox. Purified 1 ,1 ,3- trichloroacetone (34.9 g, 0.22 mol) was then added to the PCI5, which started to bubble. The flask was then sealed, removed from the glovebox and fitted with a water-cooled condenser venting via a tube to a beaker of water. The mixture was then stirred and heated to 110°C. As HCI formed, it was passed into the beaker containing water and was scrubbed out. After 3.5 h the pH of the water scrubber was no longer decreasing and so the heat was switched off and the reaction allowed to cool to room temperature. The solution was analysed by GC-MS: 1230xa (8.6%), 1230xd (13.9%).

Further results are given in Table 2. For comparison, TCA from the same batch was used in the same reaction as described above except in a ratio of 4:1 TCA:PCIs, the results of which are also given in Table 2.

Example 3- A Process for the preparation of 1230xa, 1230xd or a mixture thereof from 1 ,1 ,3-TCA (as supplied - 74% purity)

A clean, dry, 3-necked round bottomed flask (250 mL) containing a magnetic stirrer bar was loaded with PCI5 (20.94 g, 0.1 mol) in a nitrogen-purged glovebox. 1 ,1 ,3- trichloroacetone (66.1 g, 0.4 mol) was then added to the PC , which started to bubble. The flask was then sealed, removed from the glovebox and fitted with a water-cooled condenser venting via a tube to a beaker of water. The mixture was stirred and heated to reflux (165-170°C). As HCI formed, it was scrubbed out by the water, turning the pH from 7 to 1. Over time the colour of the reaction mixture changed from pale yellow to red. After 6.5 h the pH of the water scrubber was no longer decreasing and so the heat was switched off and the reaction allowed to cool to room temperature before filtering to remove solids. The solution was analysed by GC-MS.

The 1230xa and unreacted TCA co-elute (71.7%), 1230xd (12.4%), 240aa (4.1 %). Further results are given in Table 2. Table 2: Results of TCA + PCI₅ 1230xa, 1230xd or a mixture thereof

* The presence of a large quantity of unreacted TCA made it difficult to accurately quantify the products, so the numbers provided in this table are approximate. Analysis began at retention time of 9 min for Reaction 1 and 0 min for Reaction 2.

**GC- S integrated for POCb and PC . Analysis began at 0 min.

Claims

1. A process for the preparation of 1230xa, 1230xd or a mixture thereof, comprising the chlorination of 1 , 1 ,3-trichloroacetone (TCA) with a nucleophilic chlorinating agent to produce 1230xa, 1230xd or a mixture thereof.

2. A process for the preparation of a composition comprising 1230xa, 1230xd or a mixture thereof, comprising the chlorination of 1 , 1 ,3-trichloroacetone (TCA) with a nucleophilic chlorinating agent.

3. A process according to claim 1 or claim 2, wherein the nucleophilic chlorinating agent is selected from phosphorus pentachloride (PCIs), thionyl chloride and triaryl phosphine dichlorides.

4. A process according to any one of the preceding claims, wherein the chlorination reaction is conducted in the liquid phase.

5. A process according to any of the preceding claims, wherein the chlorination reaction is conducted in the presence of a solvent.

6. A process according to any one of claims 1 , 2 or 3, wherein the chlorination is conducted in the vapour phase.

7. A process according to any one of the preceding claims, wherein the chlorination is conducted at a pressure of from about 0 to about 4 Mpa (0 to 40 bara), preferably from about 0.1 to about 3 MPa (1 to 30 bara).

8. A process according to any one of the preceding claims, wherein the chlorination in conducted at a temperature of from about 0 to about 180°C, preferably from about 50 to about 150°C.

9. A process according to any one of the preceding claims, wherein the ratio of TCA: nucleophilic chlorinating agent is from about 0.1 :1 to about 40:1 , preferably from about 1 : 1 to about 20: 1.

10. A process according to any one of the preceding claims, wherein the nucleophilic chlorinating agent is PCI5.

11. A process according to any one of claims 1 to 5 or 7 to 9 for the preparation of 1230xa, 1230xd or a mixture thereof comprising the steps of;

i. adding PCIs to a solution of TCA;

ii. heating the reaction from about 1 hour to about 1000 hours; and

iii. isolating 1230xa, 1230xd or mixtures thereof from the reaction mixture.

12. A process according to any one of the preceding claims, in which 240aa is isolated as an intermediate and the 240aa is then converted into 1230xa, 1230xd or mixtures thereof.

13. A process according to any of the preceding claims, wherein the process additionally comprises a step for the purification of TCA.

14. A process according to claim 12, wherein the purification of TCA is conducted before the PCI₅ is added to the TCA.

15. The use of 1230xa in the preparation of 1234yf, wherein the 1230xa is prepared via a process according to any one of claims 1 to 14.

16. A process for the preparation of 1234yf comprising converting 1230xa 1234yf, wherein the 1230xa is prepared via a process according to any one of claims 1 to 14.

17. A process according to claim 16 comprising:

i. converting 1230xa to 1233xf, wherein the 1230xa is prepared via a process according to any one of claims 1 to 14;

ii. converting 1233xf to 244bb; and

iii. converting 244bb to 1234yf.

18. A process for preparing 1234yf which comprises a process according to any one of claims 1 to 14 and the additional step of converting 1230xa to 1234yf.

19. The use of 1230xd in the preparation of at least one hydrofluoroolefin, wherein the 1230xd is prepared via a process according to any one of claims 1 to 14.

20. A process for the preparation of at least one hydrofluoroolefin comprising converting 1230xd to at least one hydrofluoroolefin, wherein the 1230xd is prepared via a process according to any one of claims 1 to 14.

21. The use of claims 19 or a process according to claim 20 wherein the at least one hydrofluoroolefin is a hydrofluoropropene.

22. The use or process according to claim 21 , wherein the hydrofluoropropene is1234yf.

23. A process as described in Example 2 or 3.