Methods for the preparation of alkynes

Abstract

Alkyne compounds are produced by contacting a 1-alkene with chlorine, optionally in the presence of a halide salt, to form a 1,2-dichloroalkane compound, then optionally contacting the 1,2-dichloroalkane compound with a catalyst to form a chloroalkene compound, and then contacting the 1,2-dichloroalkane compound and / or the chloroalkene compound with a base and a phase transfer catalyst to form a reaction mixture comprising a 1-alkyne and / or a 2-alkyne. Representative alkynes that can be produced using this process include 1-hexyne, 2-hexyne, 2-heptyne, and the like.

Description

METHODS FOR THE PREPARATION OF ALKYNESREFERENCE TO RELATED APPLICATION

[0001] This application is being filed on December 11, 2025, as a PCT International Patent Application and claims the benefit of and priority' to U.S. Provisional Patent Application No. 63 / 733,472. filed on December 13. 2024, the disclosure of which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates generally to methods for making alkynes, and more particularly, relates to the multistep synthesis of 1 -alkyne and / or 2-alkyne products in high yield.BACKGROUND

[0003] There are many conventional synthesis schemes to produce alkynes.However, some require harsh reaction conditions or costly raw materials and, in addition, produce the desired alkyne in poor yield or with many by-products that cannot be reused or recycled. It would therefore be beneficial to have synthesis schemes that produce the desired alkyne without these drawbacks. Accordingly, it is to these ends that the present invention is generally directed.SUMMARY OF THE INVENTION

[0004] This summary’ is provided to introduce a selection of concepts in a simplified form that are further described herein. This summary is not intended to identify required or essential features of the claimed subject matter. Nor is this summary intended to be used to limit the scope of the claimed subject matter.

[0005] Processes for producing alkynes are disclosed herein. For example, a chlorination-elimination process for producing an alkyne compound can comprise (a) contacting a C3-C20 1 -alkene with chlorine, optionally in the presence of a halide salt, to form a C3-C20 1,2-di chloroalkane compound, (b) optionally, contacting the 1,2-dichloroalkane compound with a catalyst to form a C3-C20 chloroalkene compound, and (c) contacting the 1,2-dichloroalkane compound and / or the chloroalkene compound with a base and a phase1118-200-968transfer catalyst to form a reaction mixture comprising a C3-C20 1-alkyne and / or a C4-C20 2- alkyne.

[0006] Both the foregoing summary and the following detailed description provide examples and are explanatory only. Accordingly, the foregoing summary’ and the following detailed descnption should not be considered to be restrictive. Further, features or variations can be provided in addition to those set forth herein. For example, certain aspects can be directed to various feature combinations and sub-combinations described in the detailed description.BRIEF DESCRIPTION OF THE FIGURE

[0007] The following figure forms part of the present specification and is included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to this figure in combination with the detailed description of specific embodiments presented herein.

[0008] FIG. 1 is a schematic flow diagram of a chlorination-elimination process for producing an alkyne compound consistent with aspects of the present disclosure.

[0009] While the inventions disclosed herein are susceptible to various modifications and alternative forms, only a few specific embodiments have been shown by way of example in the drawing and are described in detail below. The figure and detailed descriptions of these specific embodiments are not intended to limit the breadth or scope of the inventive concepts or the appended claims in any manner. Rather, the figure and detailed written descriptions are provided to illustrate the inventive concepts to a person of ordinary skill in the art and to enable such person to make and use the inventive concepts.DEFINITIONS

[0010] To define more clearly the terms used herein, the following definitions are provided. Unless otherwise indicated, the following definitions are applicable to this disclosure. If a term is used in this disclosure but is not specifically defined herein, the definition from the IUPAC Compendium of Chemical Terminology', 2nd Ed (1997), can be applied, as long as that definition does not conflict with any other disclosure or definition applied herein, or render indefinite or non-enabled any claim to which that definition is applied. To the extent that any definition or usage provided by any document incorporated2118-200-968herein by reference conflicts with the definition or usage provided herein, the definition or usage provided herein controls.

[0011] Herein, features of the subject matter can be described such that, within particular aspects, a combination of different features can be envisioned. For each and every aspect and / or feature disclosed herein, all combinations that do not detrimentally affect the designs, compositions, processes, and / or methods described herein are contemplated with or without explicit description of the particular combination. Additionally, unless explicitly recited otherwise, any aspect and / or feature disclosed herein can be combined to describe inventive features consistent with the present disclosure.

[0012] In this disclosure, while compositions and processes / methods are described in terms of “comprising” various materials or steps, the compositions and processes / methods also can “consist essentially of’ or “consist of’ the various materials or steps, unless stated otherwise. The terms “a,” “an,” and “the” are intended to include plural alternatives, e.g., at least one. unless otherwise specified.

[0013] The terms “contacting” and “combining” are used herein to describe compositions and processes / methods in which the materials or components are contacted or combined together in any order, in any manner, and for any length of time, unless otherwise specified. For example, the materials or components can be blended, mixed, slurried, dissolved, reacted, treated, impregnated, compounded, or otherwise contacted or combined in some other manner or by any suitable method or technique. Often, contacting or combining two or more materials is a reaction between the tw o or more materials resulting in a reaction product or a reaction mixture.

[0014] Generally, groups of elements are indicated using the numbering scheme indicated in the version of the periodic table of elements published in Chemical and Engineering New s, 63(5), 27, 1985. In some instances, a group of elements can be indicated using a common name assigned to the group; for example, alkali metals for Group 1 elements, alkaline earth metals for Group 2 elements, transition metals for Group 3-12 elements, and halogens or halides for Group 17 elements.

[0015] For any particular compound or group disclosed herein, any name or structure presented is intended to encompass all conformational isomers, regioisomers, stereoisomers, and mixtures thereof that can arise from a particular set of substituents, unless otherwise specified. The name or structure also encompasses all enantiomers, diastereomers, and other optical isomers (if there are any), whether in enantiomeric or racemic forms, as well as3118-200-968mixtures of stereoisomers, as would be recognized by a skilled artisan, unless otherwise specified. For example, a general reference to hexene (or hexenes) includes all linear or branched, acyclic or cyclic, hydrocarbon compounds having six carbon atoms and 1 carboncarbon double bond; a general reference to pentane includes n-pentane, 2-methyl-butane, and 2,2-dimethylpropane; and a general reference to a butyl group includes an n-butyl group, a sec-butyl group, an iso-butyl group, and a t-butyl group.

[0016] Several types of ranges are disclosed in the present invention. When a range of any type is disclosed or claimed, the intent is to disclose or claim individually each possible number that such a range could reasonably encompass, including end points of the range as well as any sub-ranges and combinations of sub-ranges encompassed therein. For example, a step in one of the disclosed processes can be performed, or a reaction mixture can be formed, at a temperature in a range from 0 to 600 °C. By a disclosure that the temperature can be within a range from 0 to 600 °C, the intent is to recite that the temperature can be any temperature in the range and, for example, can include any range or combination of ranges from 0 to 600 °C, such as from 20 to 250 °C, from 20 to 80 °C, from 50 to 250 °C, or from 50 to 100 °C, and so forth. Likewise, all other ranges disclosed herein should be interpreted in a manner similar to this example.

[0017] In general, an amount, size, formulation, parameter, range, or other quantity or characteristic is “about” or “approximate” whether or not expressly stated to be such. Whether or not modified by the term “about” or “approximately,” the claims include equivalents to the quantities or characteristics.

[0018] In the processes disclosed and claimed herein, and not limited thereto, a product in one step can be used as a reactant in another step, or a material can be separated from a reaction mixture. For instance, when a di chloroalkane is produced in a first step and then utilized in a subsequent step, “all or any portion of’ the dichloroalkane produced in the first step can then be utilized in the subsequent step, even if not specifically stated so. Similarly, for example, when an alkyne is isolated from a reaction mixture, “all or any portion of’ the alkyne can be isolated from the reaction mixture, even if not specifically stated so. Likewise, all process steps in the specification and in the claims should be interpreted in a manner similar to these examples.

[0019] Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the typical methods and materials are herein described.4118-200-968

[0020] All publications and patents mentioned herein are incorporated herein by reference in their entirety for the purpose of describing and disclosing, for example, the constructs and methodologies that are described in the publications and patents, which might be used in connection with the presently described invention.DETAILED DESCRIPTION

[0021] Alkyne compounds are synthesized herein via a multi-step chlorinationelimination process. Halide salts can be used to improve the yield to and selectivity of the di chloroalkane compound produced from the 1 -alkene and chlorine, and phase transfer catalysts can be used to improve the yield to and selectivity of the desired alkyne product produced from the dichloroalkane and the base. Beneficially, both the halide salt and the phase transfer catalyst can be recovered and reused. For instance, as disclosed herein, lipophilic ammonium halide compounds can be used as the halide salt and the phase transfer catalyst and, after production of the desired alkyne product, can be recovered and reused in the process.

[0022] The elimination step of the chlorination-elimination process can be performed using reactive distillation to remove alkyne product as it is produced, and the reaction mixture (distillation residue) that remains can be contacted with a mixture of water and the 1- alkene to form a multiphase mixture. For organic soluble halide salts and / or phase transfer catalysts, these materials will dissolve in the organic phase (that contains the 1 -alkene) and can be readily recycled and reused in the chlorination step. Likewise, alkali metal / alkaline earth metal salts will dissolve in the aqueous phase and can be recovered and reused.

[0023] Additional benefits and advantages of the disclosed processes for producing an alkyne include (i) controlling the exotherm in step (a) via the Ch addition rate, (ii) improving the yield to and selectivity of the desired 1 ,2-chloroalkane in step (a) by a controlled chlorine addition rate and the use of the halide salt, (iii) producing a chloroalkane product in step (a) of sufficient purity such that no separation / isolation steps are required prior to its use as a reactant in step (b) and / or (c), (iv) isolating unreacted 1 -alkene at an appropriate stage (or stages) of the process and recycling the 1 -alkene into step (a) as a reactant, and (v) utilizing the same catalyst in steps (a) and (c) or utilizing the same catalyst in steps (a) and (b) and (c), thereby simplifying recovery and reuse.

[0024] In a particular aspect, step (a) utilizes the halide salt, and the halide salt can be a lipophilic quaternary ammonium salt (often C19+ or a C25+ uaternary ammonium salt), a5118-200-968representative and non-limiting example of which is trioctylmethylammonium chloride. Likewise, the phase transfer catalyst in step (c) also can be a lipophilic quaternary ammonium salt (often C19+ or a C25+ quaternary ammonium salt), a representative and non-limiting example of which is trioctylmethylammonium chloride, and any suitable base, such as NaOH (or KOH) can be utilized. If desired, an alcohol can be present in the reaction mixture of step (c), such as ethanol, propanol, butanol, and the like.CHLORINATION-ELIMINATION

[0025] The process for producing an alkyne compound using chlorination-elimination can comprise (or consist essentially of, or consist of) (a) contacting (or reacting) a C3-C20 1- alkene with chlorine, optionally in the presence of a halide salt, to form a C3-C20 1,2- di chloroalkane compound, (b) optionally, contacting the 1 ,2-di chloroalkane compound with a catalyst to form a C3-C20 chloroalkene compound, and (c) contacting (or reacting) the 1,2- dichloroalkane compound and / or the chloroalkene compound with a base and a phase transfer catalyst to form a reaction mixture comprising a C3-C20 1 -alkyne and / or a C4-C20 2-alkyne.

[0026] Generally, the features of the process (e.g., the 1-alkene, the halide salt, the dichloroalkane, the chloroalkene, the base, the phase transfer catalyst, the alkyne product, the relative amounts of the reactants, and the conditions under which the steps are conducted, among others) are independently described herein and these features can be combined in any combination to further describe the disclosed processes to produce an alkyne compound. Moreover, additional process steps can be performed before, during, and / or after any of the steps in any of the processes disclosed herein, and can be utilized without limitation and in any combination to further describe these processes, unless stated otherwise. Further, any alkyne compounds or alkyne products or alkyne product streams produced in accordance with the disclosed processes are within the scope of this disclosure and are encompassed herein.

[0027] In an aspect, the 1-alkene can have the formula R1-HC=CH2 (for instance, the I -alkene can comprise I -hexene), the 1,2-di chloroalkane compound can have the formula R1-H(C1)C-C(C1)H2, the 1 -alkyne can have the formula R^C^CH, and the 2-alkyne can have the formula R2-C =C-CH3 In these formulas, R1can be a Ci-Cis linear or branched alkyl group in one aspect, a C2-C12 linear or branched alkyl group in another aspect, a C3-C8 linear or branched alkyl group in another aspect, a C3-C6 linear alkyl group in another aspect, a C3-C4 linear alkyl group in yet another aspect, and a C4-C5 linear alkyl group in still another aspect. R2can be a C1-C17 linear or branched alkyd group in one aspect, a C2-C12 linear or6118-200-968branched alkyl group in another aspect, a C2-C8 linear or branched alkyl group in another aspect, a C2-C6 linear alkyl group in yet another aspect, and a C3-C4 linear alkyd group in still another aspect. Accordingly, the 1-alkyne can be, for instance, 1-pentyne, 1-hexyne, 1- heptyne, or 1 -octyne, as well as mixtures of combinations thereof, if desired. Similarly, the 2-alkyne compound can be, for instance, 2-pentyne, 2-hexyne, 2-heptyne, or 2-octyne, as well as mixtures of combinations thereof, if desired.

[0028] For instance, the 1-alkyne and / or the 2-alkyne can comprise 1-hexyne, 2- hexyne, or 2-heptyne, as well as any combination thereof. Thus, in one aspect, the reaction mixture can comprise the 1-alkyne, and the 1-alkyne can comprise 1-hexyne. In another aspect, the reaction mixture can comprise the 2-alkyne, and the 2-alkyne can comprise 2- hexyne.

[0029] Referring first to step (a), a C3-C20 1 -alkene is contacted (or reacted) with chlorine (Ch, typically as a gas) optionally in the presence of a halide salt to form a C3-C20 1,2-di chloroalkane compound. In one aspect, step (a) can be performed (or the dichloroalkane compound can be formed) in the presence of a diluent, i.e., a diluent other than water. For instance, the diluent can be (unreacted) 1 -alkene or a chlorine diluent to control chlorine reactivity. In another aspect, however, step (a) can be performed (or the dichloroalkane compound can be formed) in the substantial absence of a diluent, which means less than or equal to 25 wt. % of the diluent, based on the total weight of the 1 -alkene and the diluent. More often, step (a) is performed (or the dichloroalkane compound is formed) in the presence of less than or equal to 10 wt. %, less than or equal to 5 wt. %, or less than or equal 2 wt. % of the diluent, based on the total weight of the 1 -alkene and the diluent.

[0030] While not limited thereto, step (a) can be performed (or the dichloroalkane compound can be formed) at a minimum temperature of -30 °C, -15 °C, -5 °C, 5 °C, 15 °C, or 25 °C; additionally or alternatively, a maximum temperature of 500 °C, 400 °C, or 70 °C. Generally, step (a) can be performed (or the dichloroalkane compound can be formed) at a temperature in a range from any minimum temperature disclosed herein to any maximum temperature disclosed herein. Therefore, suitable non-limiting temperature ranges can include the following: from -30 to 500 °C, from -15 to 70 °C, from 15 to 400 °C, from -5 to 70 °C, from 5 to 70 °C, from 15 to 70 °C, or from 25 to 70 °C. These temperature ranges also are meant to encompass circumstances where step (a) is performed (or the dichloroalkane compound is formed) at a series of different temperatures, instead of at a single fixed temperature, wherein at least one temperature falls within the respective ranges.7118-200-968

[0031] Advantageously, it is not required to perform step (a) of the process at subambient temperature conditions. For instance, the process can be performed (or the di chloroalkane compound can be formed) at a temperature of at least 15 °C, at least 20 °C, at least 25 °C, or at least 30 °C. Any suitable maximum temperature can be utilized, but generally the upper limit on the temperature is 500 °C, 400 °C, 100 °C, 80 °C, or 70 °C. Generally, step (a) can be performed (or the dichloroalkane compound can be formed) at a temperature in a range from any minimum temperature to any maximum temperature disclosed herein.

[0032] Step (a) can be performed (or the dichloroalkane compound can be formed) at any suitable pressure, include atmospheric and sub-atmospheric pressures. Typically, however, step (a) can be performed (or the dichloroalkane compound can be formed) at a pressure in a range from atmospheric to 500 psig, from atmospheric to 100 psig, from 10 to 250 psig, from 10 to 100 psig, or from 250 to 500 psig, and the like.

[0033] While not limited thereto, the molar ratio of 1 -alkene: chlorine (Ch) in step (a) often can fall within a range from 5: 1 to 1 :5. For instance, in one aspect, the molar ratio of 1- alkene: chlorine (Ch) can range from 3: 1 to 1:3, from 3: 1 to 1: 1 in another aspect, from 2: 1 to 1 :2 in yet another aspect, and from 2: 1 to 1 : 1 in still another aspect.

[0034] In some aspects, step (a) can be performed (or the di chloroalkane compound can be formed) without the halide salt. In other aspects, however, step (a) can be performed (or the dichloroalkane compound can be formed) in the presence of the halide salt. The amount of the halide salt in step (a) is not particularly limited, but often can range from 0. 1 to 10 wt. %, based on the amount of the 1 -alkene. Other suitable ranges for the amount of the halide salt, based on the 1 -alkene in step (a), include from 0.5 to 5 wt. %, from 0.5 to 2.5 wt. %, from 1 to 10 wt. %, or from 1 to 5 wt. %. While not wishing to be bound by theory, it is believed that the presence of the halide salt increases the [Cl] in the 1-alkene and increases the yield to and selectivity of the desired 1,2-di chloroalkane in step (a). Any suitable fluoride salt, chloride salt, bromide salt, or iodide salt, as well as combinations thereof, can be used as the halide salt in step (a). In some aspects, the halide salt in step (a) can comprise a C15+ quatemary ammonium salt, and more often, a C19+ quaternary ammonium salt or a C25+ quatemary ammonium salt. Representative examples of suitable halide salts include sodium chloride (NaCl), tetrabutylammonium chloride, tributylhexadecyl phosphonium chloride, trioctylmethylammonium chloride, a methyltrialkyl(Cs-Cio) ammonium chloride, and the like, or combinations thereof. If the halide salt is water soluble, it can be recovered from the8118-200-968aqueous phase of a multiphase mixture, as described herein, and reused. If the halide salt is organic soluble, it can be recovered from the organic phase of the multiphase mixture, and reused.

[0035] It is also contemplated that the halide salt in step (a) does not have to be a halide salt and, instead, can be ammonium hydroxide or other non-halide salt (or non-halide phase transfer catalyst). Accordingly, step (a) can be performed (or the dichloroalkane compound can be formed) in the presence of a non-halide salt (or a non-halide phase transfer catalyst).

[0036] Beneficially, the overall conversion of the 1 -alkene in step (a) is relatively high, and ordinarily at least 80 wt. %. More often, the overall conversion of the 1 -alkene in step (a) is at least 85 wt. %; alternatively, at least 90 wt. %; alternatively, at least 95 wt. %; alternatively, at least 98 wt. %; or alternatively, at least 99 wt. %. The overall conversion is the 1 -alkene conversion in a batch process, and the overall conversion is the 1 -alkene conversion after more than one pass (e.g., multiple passes) in a continuous process, such as with recycle of the reactant in excess. For example, if the 1 -alkene is used in excess, it can be recycled and reacted with the chlorine in one or more passes. In a continuous process, the single pass conversion may be at least 10 wt. %, at least 20 wt. %, at least 30 wt. %, at least 50 wt. %, or at least 70 wt. %, but the overall conversion (after more than one pass) generally will be at least 80-90 wt. %.

[0037] Also beneficially, the molar yield of the dichloroalkane compound in step (a) is relatively high. For instance, based on the 1 -alkene in step (a), the molar yield of the dichloroalkane is typically at least 75 mol %, and more often, at least 80 mol %, at least 85 mol %, at least 90 mol %, at least 95 mol %, or at least 98 mol %. However, it should be noted that lower molar yields to the dichloroalkane of less than 80-90 mol %, such as 50 mol %, may be acceptable, provided that the only materials in the reaction product are the 1- alkene and the 1,2-di chloroalkane. The 1 -alkene can be isolated and re-used in step (a).

[0038] The reaction product formed in step (a) can be further processed to isolate or separate various reaction products and materials from the reaction product. For example, the process can comprise the step of isolating (all or any portion of) unreacted chlorine gas from the dichloroalkane compound in step (a), and this can be accomplished using any suitable gas-liquid separation technique. For instance, the chlorine gas can be flashed from or separated by density from the liquid product(s). Then, (all or any portion of) the unreacted9118-200-968chlorine gas can be recycled into step (a) to improve overall conversion and yield if desired, e.g., to react with the 1-alkene.

[0039] Additionally or alternatively, the process can further comprise a step of isolating (all or any portion of) unreacted 1-alkene from the di chloroalkane compound in step (a), and this can be accomplished using any suitable separation technique, such as extraction, distillation, wiped fdm evaporation, and the like. Then, (all or any portion of) the unreacted 1-alkene can be recycled into step (a) to improve overall conversion and yield if desired, e.g., to react with the chlorine.

[0040] Referring now to step (b), in one aspect, step (b) is not performed and the dichloroalkane compound is used as the starting material for step (c). Alternatively, in another aspect, step (b) is performed, and the 1,2-di chloroalkane compound is contacted (or reacted) with a catalyst to form a C3-C20 chloroalkene compound. Any suitable catalyst can be used in step (b). but generally a solid basic catalyst is used, with representative examples including alumina, activated carbon, and the like. Combinations of two or more suitable catalysts can be used in step (b), if desired.

[0041] While not limited thereto, step (b) can be performed (or the chloroalkene compound can be formed) at a minimum temperature of 25 °C, 100 °C, 150 °C, or 250 °C; additionally or alternatively, a maximum temperature of 500 °C, 450 °C, or 400 °C. Generally, step (b) can be performed (or the chloroalkene compound can be formed) at a temperature in a range from any minimum temperature disclosed herein to any maximum temperature disclosed herein. Therefore, suitable non-limiting temperature ranges can include the following: from 25 to 500 °C. from 100 to 500 °C, from 100 to 400 °C, from 150 to 450 °C, or from 250 to 400 °C. These temperature ranges also are meant to encompass circumstances where step (b) is performed (or the chloroalkene compound is formed) at a series of different temperatures, instead of at a single fixed temperature, wherein at least one temperature falls within the respective ranges.

[0042] Step (b) can be performed (or the chloroalkene compound can be formed) at any suitable pressure, include atmospheric and sub-atmospheric pressures. Typically, however, step (b) can be performed (or the chloroalkene compound can be formed) at a pressure in a range from atmospheric to 500 psig, such as from atmospheric to 100 psig, from 10 to 250 psig. from 10 to 100 psig, or from 250 to 500 psig, and the like.

[0043] Although not limited thereto, the amount of the catalyst in step (b), based on the 1,2-di chloroalkane compound, often can fall within a range from 0. 1 to 20 wt. %. More10118-200-968often, the amount of catalyst is from 0.2 to 15 wt. %; alternatively, from 0.5 to 12 wt. %; alternatively, from 1 to 12 wt. %; or alternatively, from 1 to 8 wt. %.

[0044] While not wishing to be bound by the following theory', it is believed that the first chlorine of the dichloroalkane can be conveniently removed by contacting the dichloroalkane wi th a catalyst, typically at elevated temperature, thereby forming HC1 and vinyl chlorides (chloroalkenes). By including step (b), the amount of the salt formed in step (c) can be reduced by one-half, advantageously improving the dow nstream separation procedures.

[0045] Referring now to step (c), the 1,2-di chloroalkane compound and / or the chloroalkene compound, in any suitable relative amounts, can be contacted (or reacted) with a base and a phase transfer catalyst to form a reaction mixture comprising a C3-C20 1 -alkyne and / or a C4-C20 2-alkyne. The base in step (c) can comprise an alkali metal oxide, an alkali metal hydroxide, an alkali metal alkoxide, an alkali metal amide, an alkali metal hydride, an alkaline earth metal oxide, an alkaline earth metal hydroxide, an alkaline earth metal alkoxide, an alkaline earth metal amide, or an alkaline earth metal hydride. Combinations of two or more of these bases can be utilized, if desired. The amount of the base in step (c) is not particularly limited, and any suitable amount can be utilized. Nonetheless, typical molar equivalent ratios of the base to the 1,2-di chloroalkane compound and the chloroalkene compound in step (c), can fall within a range from 5: 1 to 1:5, from 1.1: 1 to 5: 1, from 1.2: 1 to 4: 1, from 1.5: 1 to 4: 1, from 1 : 1 to 2:1, or from 1.8: 1 to 2.6: 1.

[0046] Specific non-limiting examples of the base in step (c) can include, for instance, sodium hydroxide, potassium hydroxide, potassium t-butoxide, sodium butoxide. sodium amide, sodium t-butoxide, cesium hydroxide, methyl lithium, n-butyl lithium, secbutyl lithium, tert-butyl lithium, n-hexyl lithium, calcium hydroxide, magnesium hydroxide, and the like, or combinations thereof. In an aspect, the base can encompass a suitable mineral base having a pKa above 10 as well as any suitable organic base having a pKa above 10. In another aspect, the base can encompass a suitable base matenal that is strong enough to remove the Cl, but not strong enough to deprotonate the alkyne product. In another aspect, the base can include phosphates such as tripotassium phosphate and related compounds. In yet another aspect, the base can comprise tetraethylammonium or tetrabutylammonium hydroxide, and similar derivatives. In still another aspect, the base can act both as the base component in step (c) and the phase transfer catalyst component in step (c). For example,11118-200-968tetraethylammonium or tetrabutylammonium hydroxide can act both as the base component and the phase transfer catalyst component.

[0047] When the base comprises an alkali metal and / or an alkaline earth metal compound, the alkali metal salt and / or the alkaline earth metal salt in the reaction mixture of step (c) can comprise LiCl, NaCl, KC1, CsCl, and the like, as well as any combination thereof.

[0048] While not a requirement, step (c) can be performed (or the reaction mixture can be formed) in the presence of a reaction medium, also referred to as a solvent or diluent. When used, the composition of the reaction medium in step (c) is not particularly limited. For instance, the reaction medium can comprise a protic solvent, or alternatively, the reaction medium can comprise a polar non-protic solvent, or alternatively, the reaction medium can comprise a non-polar solvent (e.g., toluene, alkanes such as cyclohexane and polyalphaolefins, diesel fuel, etc.).

[0049] Specific examples of suitable solvents for the reaction medium can include, but are not limited to, dimethylsulfoxide, isopropanol, ethanol, butanol, a (poly) ethylene glycol, a (poly) propylene glycol, dihydrolevoglucosenone, a glyme, a mono-glyme, an ether, a polyether, water, N-methylpyrrolidone, dimethylcarbonate, sulfolane, dimethylformamide, mineral oil, decalin, tetralin, toluene, cyclohexane, a diesel fuel, a polyalphaolefin (PAO), an isoparaffin or a mixture of alkanes, and the like. Combinations or two or more of these solvents can be used as the reaction medium in step (c), if desired.

[0050] While not wishing to be bound by the following theory', it can be beneficial to use a polar solvent as the reaction medium in step (c) to improve downstream separations of the salt (e.g., NaCl) formed via liquid-liquid separation of aqueous and organic phases. Often, the use of a non-polar solvent results in a slower reaction to form the alkyne in step (c). Another consideration for the reaction medium in step (c) also can be a larger boiling point difference versus that of the alkyne to improve downstream separations, e.g., via distillation. Optionally, the reaction medium can further comprise generally small amounts of surfactants, as needed.

[0051] In one aspect, the phase transfer catalyst can comprise an alcohol, a diol, a glycol (e.g., a PEG or a PPG), a polyol, an ether, a glyme, a mono-glyme, an ammonium salt, a phosphonium salt, and the like, or a combination thereof. In another aspect, the phase transfer catalyst can comprise a C15+ quaternary' ammonium salt, and more often, a C19+ quatemary ammonium salt or a C25+ quaternary7ammonium salt. In yet another aspect, the12118-200-968phase transfer catalyst can comprise a polyethylene glycol, methanol, ethanol, propanol, pinacol (2,3-dimethylbutane-2,3-diol), tetrabutyl ammonium chloride, tributylhexadecyl phosphonium chloride, trioctylmethylammonium chloride, a methyltrialkyl(C8-Cio) ammonium chloride, and the like, or a combination thereof. Typically, when both the reaction medium and the phase transfer catalyst are present, the phase transfer catalyst is soluble in the reaction medium. In yet another aspect, the phase transfer catalyst can comprise a lipophilic quaternary ammonium salt, a hydrophilic quaternary ammonium salt, a lipophilic quaternary phosphonium salt, or a combination thereof. The amount of the phase transfer catalyst in step (c) is not particularly limited, and any suitable amount can be utilized. Nonetheless, typical amounts of the phase transfer catalyst in step (c), based on the 1,2- dichloroalkane compound and the chloroalkene compound, can fall within a range from 0. 1 to 20 wt. %, from 0.2 to 15 wt. %, from 0.5 to 8 wt. %, from 1 to 10 wt. %, or from 3 to 7 wt. %.

[0052] While not limited thereto, step (c) can be performed (or the reaction mixture can be formed) at a minimum temperature of 0 °C, 20 °C, or 50 °C; additionally or alternatively, a maximum temperature of 600 °C, 250 °C, 100 °C or 80 °C. Generally, step (c) can be performed (or the reaction mixture can be formed) at a temperature in a range from any minimum temperature disclosed herein to any maximum temperature disclosed herein. Therefore, suitable non-limiting temperature ranges can include the following: from 0 to 600 °C, from 20 to 250 °C, from 20 to 80 °C, from 50 to 250 °C, or from 50 to 100 °C. These temperature ranges also are meant to encompass circumstances where step (c) is performed (or the reaction mixture is formed) at a series of different temperatures, instead of at a single fixed temperature, wherein at least one temperature falls within the respective ranges.

[0053] Step (c) can be performed (or the reaction mixture can be formed) at any suitable pressure, include atmospheric and sub-atmospheric pressures. Typically, however, step (c) can be performed (or the reaction mixture can be formed) at a pressure in a range from atmospheric to 1000 psig, or at any pressure or pressure range sufficient to keep the reaction mixture in the liquid phase.

[0054] In a particular aspect, step (c) can be performed (or the reaction mixture can be formed) using reactive distillation, and this can be conducted at any suitable combination of temperature and pressure. Using reactive distillation, alkyne (1 -alkyne and / or 2-alkyne) and optionally vinyl chloride products can be removed from the reaction mixture as they are formed.13118-200-968

[0055] Beneficially, the molar yield of the 1 -alkyne and / or the 2-alkyne in the reaction mixture in step (c) is relatively high. For instance, based on the 1-alkene in step (a), when the 1 -alkyne is the primary' product, the molar yield of the 1 -alky ne is ty pically at least 75 mol %, and more often, at least 80 mol %, at least 85 mol %, at least 90 mol %, at least 95 mol %, or at least 98 mol %. Likewise, when the 2-alkyne is the primary product, the molar yield of the 2-alkyne, based on the 1-alkene in step (a), is at least 75 mol %, at least 80 mol %, at least 85 mol %, at least 90 mol %, at least 95 mol %, or at least 98 mol %.

[0056] In some aspects, the reaction mixture comprises (or consists essentially of, or consists of) the 1-alkyne. To promote formation of the 1 -alky ne, it is believed that it is advantageous to separate or isolate the 1-alkyne from the reaction mixture as it is being formed or produced, so as to minimize isomerization to internal alkynes. Typically, step (c) is performed at a temperature above the boiling point of the 1-alkyne, although this is not a requirement.

[0057] In other aspects, the reaction mixture comprises (or consists essentially of, or consists of) the 2-alkyne. To promote formation of the 2-alkyne, it is believed that it is advantageous to use excess of the base (e.g., alkali metal / alkaline earth metal compound) in step (c) and generally to conduct step (c) at a higher temperature, so as to favor isomerization to the 2-alkyne. Further, it is also preferable to not use reactive distillation.

[0058] The reaction mixture in step (c) can be further processed to isolate or separate various reaction products and materials from the reaction mixture. For example, the process can comprise the steps of contacting the reaction mixture with water to form a multiphase mixture, and then separating (all or any portion of) the 1-alkyne and / or the 2-alkyne and (all or any portion of) the optional reaction medium from the multiphase mixture using phase separation and / or decanting. In this regard, the organic phase (which contains the 1-alkyne and / or the 2-alkyne) of the multiphase mixture can be separated from an aqueous phase.

[0059] In another example, the process can comprise the steps of contacting the reaction mixture with water and the 1-alkene to form a multiphase mixture, and then separating (all or any portion of) the base, an optional alkali metal salt and / or alkaline earth metal salt, and the phase transfer catalyst based on solubility from the multiphase mixture, and this can be accomplished using phase separation and / or decanting.

[0060] When the halide salt is used in step (a), the reaction mixture can further comprise the halide salt, and thus the multiphase mixture can comprise the halide salt. Likewise, the phase transfer catalyst is used in step (c), so the reaction mixture can further14118-200-968comprise the phase transfer catalyst, and thus the multiphase mixture can comprise the phase transfer catalyst. The respective selection of the halide salt and the phase transfer catalyst (and solubility properties) will determine whether the halide salt in present in the aqueous phase or the organic phase of the multiphase mixture and whether the phase transfer catalyst is present in the aqueous phase or the organic phase of the multiphase mixture. For instance, alcohol phase transfer catalysts and tetrabutyl ammonium chloride will be in the aqueous phase, whereas tributylhexadecyl phosphonium chloride will be in the organic phase. In particular aspects of this invention, it is beneficial (for recovery and reuse) to utilize both halide salts and phase transfer catalysts that are soluble in the organic phase.Trioctylmethylammonium chloride and tetraoctylammonium chloride are other examples of lipophilic phase transfer catalysts.

[0061] Additionally, the process also can comprise a step of separating (all or any portion of) the alkali metal salt and / or the alkaline earth metal salt, residual base, and water from the multiphase mixture using phase separation and / or decanting. In this regard, the aqueous phase of the multiphase mixture is isolated.

[0062] The aqueous phase can be treated further. For instance, the process can further comprise a step of subjecting (all or any portion of) the separated water and alkali metal salt and / or alkaline earth metal salt (in the aqueous phase) to a chloroalkali electrolysis process to produce a metal compound (e.g., a metal hydroxide such as NaOH), CI2, and H2. Advantageously, (all or any portion of) the metal compound (e.g., a metal hydroxide such as NaOH) can be recycled into step (c) as a reactant and reused. Similarly, since the 1,2- dichloroalkane compound is synthesized in step (a), the recovered Ch can be used as a reactant to produce the dichloroalkane compound. Additionally or alternatively, precipitated alkali metal salt and / or alkaline earth metal salt, such as NaCl, can be removed from the aqueous phase via filtration or other suitable technique.

[0063] Likewise, the organic phase can be treated further. The process can further comprise a step of isolating (all or any portion of) the 1 -alkyne and / or the 2-alkyne from the reaction medium (or the reaction mixture) to form an alkyne product using any suitable technique. Distillation or wiped film evaporation can be utilized, although other suitable separations techniques based on differences in boiling points can be used. Advantageously, (all or any portion of) the isolated reaction medium (solvent or diluent) can be reused; the isolated reaction medium can be recycled into step (c), if desired.15118-200-968

[0064] The overall yield of the 1 -alkyne and / or the 2-alkyne can vary over a wide range based on how step (a) and step (b) and step (c) are performed. Nonetheless, the overall molar yield of the (isolated) 1 -alkyne and / or the 2-alkyne (in the alkyne product), based on the 1 -alkene in step (a), can be at least 60%, and in some instances, at least 70%, at least 80%, at least 85%, at least 90%, or at least 92%.

[0065] The purity of the 1 -alkyne and / or the 2-alkyne in the alkyne product or product stream is typically very high, such as at least 95 wt. %, at least 97 wt. %, at least 98 wt. %, at least 99 wt. %, or at least 99.5 wt. %. For instance, the alkyne product or product stream can have an allene content of less than or equal to 3 wt. %, and more often, less than or equal to 2 wt. %, less than or equal to 1 wt. %, less than or equal to 5000 ppm, less than or equal to 1000 ppm, less than or equal to 500 ppm, less than or equal to 250 ppm, less than or equal to 150 ppm, less than or equal to 100 ppm, less than or equal to 50 ppm, less than or equal to 25 ppm, or less than or equal to 10 ppm (by weight). Optionally, the allene in the alkyne product or product stream can be reacted to from a 2-alkyne or a 1,3-diene or 2.4- diene.

[0066] Additionally or alternatively, the alkyne product or product stream can have a very low propargyl alcohol content (or a ketone content) of less than or equal to 250 ppm, and more often, less than or equal to 150 ppm, less than or equal to 100 ppm. less than or equal to 50 ppm, less than or equal to 25 ppm, or less than or equal to 10 ppm (by weight). Propargyl alcohol can be formed by the reaction of the alky ne and oxygen, and therefore suitable storage of the alkyne product without exposure to oxygen, such as storage in an inert gas or nitrogen atmosphere, is often required, and additionally or alternatively, an antioxidant is combined with the alkyne product or product stream as soon as it is separated / isolated.

[0067] Additionally or alternatively, the alkyne product or product stream can have a very7low peroxide content of less than or equal to 2000 ppm, and more often, less than or equal to 1000 ppm, less than or equal to 500 ppm. less than or equal to 250 ppm, less than or equal to 150 ppm, less than or equal to 100 ppm, less than or equal to 50 ppm, less than or equal to 25 ppm, or less than or equal to 10 ppm (by weight). Likewise, the alkyne product or product stream can have a very low vinylchloride content of less than or equal to 5000 ppm, and more often, less than or equal to 1000 ppm, less than or equal to 500 ppm, less than or equal to 250 ppm. less than or equal to 150 ppm, less than or equal to 100 ppm, less than or equal to 50 ppm, less than or equal to 25 ppm, or less than or equal to 10 ppm (by weight).16118-200-968

[0068] In one aspect, the alkyne product can comprise at least 70 wt. %, and more often, at least 85 wt. %, at least 90 wt. %, at least 92 wt. %, at least 95 wt. %, at least 97 wt. %, or at least 99 wt. % of 1 -hexyne. In another aspect, the alkyne product can comprise at least 70 wt. %, and more often, at least 85 wt. %, at least 90 wt. %, at least 92 wt. %, at least 95 wt. %, at least 97 wt. %, or at least 99 wt. % of 2-hexyne. In yet another aspect, the alkyne product can comprise at least 70 wt. %, and more often, at least 85 wt. %, at least 90 wt. %, at least 92 wt. %, at least 95 wt. %, at least 97 wt. %, or at least 99 wt. % of 2-heptyne.

[0069] Additionally or alternatively, in some aspects, the alkyne product can comprise at least 10 ppm, at least 50 ppm. at least 100 ppm. at least 250 ppm, at least 500 ppm, at least 1000 ppm, or at least 5000 ppm (by weight), and less than or equal to 12 wt. %, less than or equal to 10 wt. %, less than or equal to 7 wt. %, less than or equal to 5 wt. %, less than or equal to 2 wt. %, or less than or equal to 1 wt. % of 1 -hexene (or 1 -heptene, or C3-C20 1 -alkenes). Generally, the amount of the 1 -alkene in the alkyne product can range from any minimum amount (ppm) to any maximum amount (wt. %) disclosed herein.

[0070] Referring now to FIG. 1, which illustrates a schematic flow diagram of a chlorination-elimination process 100 for producing an alkyne compound consistent with an aspect of the present disclosure. Chlorine 102, carbon tetrachloride 104, and 1-hexene 106 are introduced into chlorination reactor 110 and reacted at 50 °C and 50 psig to produce reaction mixture 115 containing 1,2-dichlorohexane and carbon tetrachloride. The yield of 1 ,2-di chlorohexane is 100 mol % based on the feed stream of 1-hexene 106. Reactor mixture 115 is fed to first fractionation unit 120, which can include one or more distillation columns, and carbon tetrachloride (with a boiling point of 77 °C) is isolated at 98 mol % yield, and optionally recycled into the feed stream of carbon tetrachloride 104.

[0071] An isolated stream of 1,2-dichlorohexane 125 (with a boiling point of 174 °C) also exits first fractionation unit 120 and is fed to elimination reactor 140, and reacted with mineral oil 132, sodium hydroxide 134, and ethylene glycol 136 at 175 °C and 500 psig to produce reaction mixture 148. Reaction mixture 148 contains 2-hexyne, sodium chloride, sodium hydroxide, mineral oil, and ethylene glycol. Yield of 2-hexyne in reaction mixture 148 is 95 mol % based on 1,2-dichlorohexane 125 fed to elimination reactor 140. Reaction mixture 148 is mixed with water 144 in phase separation vessel 150 at a temperature sufficient for all of the sodium chloride to dissolve in water 144. Aqueous phase 154 and organic phase 158 are then discharged from phase separation vessel 150. Aqueous phase 15417118-200-968contains water, sodium chloride, and sodium hydroxide, while organic phase 158 contains 2- hexyne, mineral oil, and ethylene glycol.

[0072] Organic phase 158 is fed to second fractionation unit 160, which can include one or more distillation columns, in which 2-hexyne product 164 is isolated due to its low boiling point of 85 °C at a yield of 97 mol % based on 2-hexyne in organic phase 158. Mineral oil 168 (with a boiling point of 260 °C) is recovered from second fractionation unit 160 and recycled into the feed stream of mineral oil 132.EXAMPLES

[0073] The invention is further illustrated by the following examples, which are not to be construed in any way as imposing limitations to the scope of this invention. Various other aspects, modifications, and equivalents thereof which, after reading the description herein, can suggest themselves to one of ordinary skill in the art without departing from the spirit of the present invention or the scope of the appended claims.EXAMPLES 1-6

[0074] The reaction scheme for experimentation relating to step (c) of the chlorination-elimination process is shown below.

[0075] Examples 1-6 were performed in accordance with the following procedure and are summarized in Table 1. In a dry 20 mL screw-top vial equipped with a magnetic stirrer and placed under a constant stream of nitrogen, 0.5 g of 1,2-di chlorohexane, 4.5 g of the solvent and the base (2 equivalents) shown in Table 1 were added. After stirring at the temperature as specified in Table 1 for 2 hr, an aliquot of the reaction mixture was quenched in a water / pentane mixture (1 / 1 by volume) and the product selectivity7(mol %) was assessed by gas chromatography analysis using the ratio of starting material, products, and vinyl chloride intermediates. Examples 1-6 demonstrate that certain combinations of solvent and base can selectively produce 1 -hexyne when the quantity of base is kept at 2 equivalents.18118-200-968Table 1EXAMPLES 7-12

[0076] The reaction scheme for experimentation relating to step (c) of the chlorination-elimination process is shown below.

[0077] Examples 7-12 w ere performed in accordance with the following procedure and are summarized in Table 2. In a dry 20 mL screw -top vial equipped with a magnetic stirrer and placed under a constant stream of nitrogen. 0.5 g of 1,2-di chlorododecane, 4.5 g of the solvent, and the base (equivalents shown in Table 2) were added. After stirring at the temperature as specified in Table 2 for 24 hr, an aliquot of the reaction mixture was quenched in a w ater / pentane mixture (1 / 1 by volume) and the product selectivity (mol %) w as assessed by gas chromatography analysis using the ratio of starting material, products, and vinyl chloride intermediates. Examples 7-12 demonstrate that certain combinations of solvent and base can produce 2-dodecyne selectively or a mixture of 1 -dodecyne and 2-dodecyne. Thus, the reaction is not limited to hexyne derivatives, but longer alkanes may be less reactive.19118-200-968Table 2EXAMPLES 13-19

[0078] The reaction scheme for experimentation relating to step (c) of the chlorination-elimination process is shown below.

[0079] Examples 13-19 were performed in accordance with the following procedure and are summarized in Table 3. In a dry 50 mL round-bottom flask equipped with a magnetic stirrer and a short path distillation column, 5 g of 1,2-dichlorohexane, 20 mL of the solvent and the base (2.5 equivalents) shown in Table 3 were added. The reaction mixture was brought to reflux and the product was collected from the distillation receiving flask. The reaction yield was assessed by weight and the product selectivity was assessed by gas chromatography analysis using the ratio of starting material, products, and vinyl chloride20118-200-968intermediates. Examples 13-19 demonstrate that certain combinations of solvent and base can produce 1 -hexyne selectively when the alkyne product is removed from the reaction as it is being produced.Table 3* 20 mol % of polyethylene glycol 400 was added as a phase transfer catalyst.** 20 mol % of potassium tert-butoxide was added.EXAMPLE 20

[0080] Example 20 was performed in accordance with the following procedure. The reaction mixture of Example 17 was placed into a separatory funnel and 15 mL of water was added. The separatory funnel was agitated. After 15 min, the organic phase was decanted away from the aqueous phase. The product selectivity (mol %) was assessed by gas chromatography analysis using the ratio of starting material, products, and vinyl chloride intermediates. A mixture containing 1-hexyne (50 mol %) and vinyl chlorides (50 mol %) was obtained. Example 20 demonstrates the step of separating the KC1 salt by-product from the reaction mixture via water addition followed by phase separation.

[0081] If the reaction mixture of one of the examples in which DMSO is the solvent is mixed with water as above, electrodialysis can be used to separate a DMSO / water / salt mixture to recover and reuse the DMSO and to isolate a brine solution.21118-200-968EXAMPLE 21

[0082] Example 21 was performed in accordance with the following procedure. In a dry 50 mL round-bottom flask equipped with a magnetic stirrer and a reflux condenser, 5 g of 1,2-di chlorododecane, 20 mL of light mineral oil, and 1 g of basic alumina were added. The reaction mixture was heated to 350 °C external temperature and refluxed for 2 hr. The product selectivity (mol %) was assessed by gas chromatography analysis using the ratio of starting material, products, and vinyl chloride intermediates. A mixture containing vinyl chlorides (100 mol %) was obtained. Example 21 demonstrates that the first hydrogen chloride elimination step can be performed thermally.EXAMPLES 22-27

[0083] The reaction scheme for experimentation relating to step (a) of the chlorination-elimination process is shown below.

[0084] Examples 22-27 were performed in accordance with the following procedure and are summarized in Table 4. In a 4-neck 500-mL round bottom flask equipped with a thermowell, a pressure relief device, a gas diffuser, and a reflux condenser, was added 200 g of 1 -hexene and various additives to be tested. The reaction mixture was cooled with an ice bath while a mixture of chlorine and nitrogen gas was introduced into the flask through the gas diffuser. The rate of gas addition was set so that the reaction mixture temperature was kept between 0 and 20 °C.

[0085] Without being bound by theory, it is believed that the reaction of 1 -hexene with chlorine forms a short-lived chloronium intermediate which then can further react to produce the desired 1,2-di chlorohexane product. However, this chloronium intermediate also can react to form undesirable by-products, including 1 -chloro-2-hexene, 1,3-dichlorohexane, and 1, 2, 3-tri chlorohexane. Surprisingly, as demonstrated in Examples 22-27, the presence of an excess of chloride ions in the reaction mixture drastically improves the selectivity of the chlorination step to the desired 1,2-di chloroalkane product.22118-200-968

[0086] Example 22 was conducted with a brine solution with 15 wt. % NaCl relative to the 1 -hexene and 50 wt. % water relative to the 1 -hexene. Example 22 had a selectivity to the desired chloroalkane product of 53 mol % at an excellent conversion of the 1 -hexene (94 mol %). In comparison, Example 23 employed 15 wt. % (based on 1 -hexene) of a quaternary ammonium chloride in addition to the aqueous chloride solution and demonstrated a significant increase in selectivity' to 73 mol %. However, this increase in selectivity was accompanied by a reduction in conversion.

[0087] Unexpectedly, Example 24 resulted in further improvement by the use of an organic solvent in place of the water. Surprisingly, selectivity’ to the desirable 1,2- dichloroalkane product increased even further to 96 mol %. Conversion of the 1 -hexene w as much improved at 69 mol % by substituting the w ater with chloroform as an organic solvent.

[0088] The excellent results of Example 24 were also observed in Examples 25-26. In Example 25, an alternate quaternary ammonium chloride (Adogen 464 is a quaternary ammonium chloride salt: methyltrialkyl(C8-Cio) ammonium chloride) was employed and provided similarly excellent selectivity with 51 mol % conversion. In Example 26, the ratio of CI2 / N2 w as reduced, how ever, despite the reduction in Ch pressure, it w as found that the excellent selectivity remained and conversion increased. Without being bound by theory, the presence of an excess of the chloride ion within the reaction mixture (as opposed to the concentration of Ch) appeared to drive the unexpected improvements in selectivity and conversion. Indeed, the reduction of the ratio of CI2 / N2 was accompanied by an increase in the conversion of the 1 -hexene to 89 mol %, incredibly without any sacrifice to the 96 mol % selectivity to the dichloroalkane.

[0089] Example 27 demonstrates that a different alternative quaternary ammonium chloride salt (Aliquat 336, trioctylmethylammonium chloride) resulted in improved selectivity, even in the absence of NaCl in the reaction mixture, and with a reduced CI2 / N2 ratio. In these Examples, it was demonstrated that lipophilic chloride salts may provide a source of chloride ions to the reaction mixture that may stabilize the chloronium intermediate and prevent further reaction into undesirable byproducts. The selectivity of the reaction remained, even in the absence of NaCl as a source of chloride ions.23118-200-968Table 4EXAMPLES 28-34

[0090] The reaction scheme for experimentation relating to step (c) of the chlorination-elimination process is shown below.

[0091] Examples 28-34 were performed in accordance with the following procedure and are summarized in Table 5. Four distinct methods were evaluated for yield and selectivity7for the dehydrochlorination of 1,2-di chlorohexane to produce 1 -hexyne. Generally, a 2-neck 500-mL round bottom flask was equipped with an addition funnel and a reflux condenser. To the flask was added either KOH pellets (22.6 g) or NaOH pellets (16. 1 g). The flask was heated to 80 °C + / - 5 °C and heat tape was used to maintain overhead temperature at 100°C + / - 5°C. Using the addition funnel, 25 g of 1 ,2-dichlorohexane was added over a span of 1 hour. After the addition was complete, the flask temperature was24118-200-968raised to 125°C + / - 5 °C for 0.5 hour and then to 150 °C + / - 5 °C for 0.5 hour. The product was analyzed by gas chromatography.

[0092] In Method A and Method C, the hydroxide was KOH; in Methods B and D, the hydroxide was NaOH. For Method A and Method B. the catalyst was added to the flask with the hydroxide prior to heating, and 1,2-dichlorohexane was added separately from the catalyst. For Method C and Method D, the catalyst was added to the flask as a mixture with 1,2- dichlorohexane.

[0093] With the exception of Example 33 employing diethylene glycol as a catalyst, each of the Examples had an excellent molar conversion of the dichlorohexane of 98-99+ mol %. Examples 31-32 used a lipophilic ammonium halide salt as a catalyst, and showed surprisingly improved selectivity to 1 -hexyne, particularly as compared to Examples 29-30.

[0094] In sum, the use of lipophilic ammonium halide salts appears beneficial for both the chlorination and elimination steps. Further, using suitable separation / isolating techniques, the lipophilic ammonium halide salts can be conveniently recovered and reused. For instance, the distillation residue of the elimination step can be contacted with a mixture of water and 1- hexene, such that the lipophilic ammonium halide salt catalyst dissolves into 1 -hexene and can be recycled into the chlorination step.

[0095] Reactive distillation in which the 1 -alkyne product is withdrawn from the reaction mixture as it is being formed, and the addition of a mixture of 1,2-dichlorohexane and catalyst to the base at reaction temperature, improve the selectivity of the desired alkyne product. Conditions where 1-hexyne is exposed to a strong base and / or high temperature should be minimized to prevent the formation of 1,2-hexadiene and 2-hexyne by-products.25118-200-968Table 5.26118-200-968

Claims

CLAIMSWhat is claimed is:1 . A process for producing an alkyne compound, the process comprising:(a) contacting a C3-C20 1 -alkene with chlorine, optionally in the presence of a halide salt, to form a C3-C20 1,2-di chloroalkane compound;(b) optionally, contacting the 1 ,2-di chloroalkane compound with a catalyst to form a C3-C20 chloroalkene compound; and(c) contacting the 1,2-di chloroalkane compound and / or the chloroalkene compound with a base and a phase transfer catalyst to form a reaction mixture comprising a C3-C20 1- alkyne and / or a C4-C20 2-alkyne.

2. The process of claim 1, wherein: the 1 -alkene has the formula RJ-HOCLL; the 1,2-di chloroalkane compound has the formula R1-H(C1)C-C(C1)H2; the 1 -alkyne has the formula RJ-C^CH; the 2-alkyne has the formula R2-C=C-CH3;R1is a Ci-Cis linear or branched alkyd group; andR2is a C1-C17 linear or branched alky 1 group.

3. The process of claim 2, wherein:R1is a C2-C12 linear or branched alkyl group, a Cs-Cs linear or branched alkyd group, a C3-C6 linear alkyl group, or a C4-C5 linear alkyl group; andR2is a C2-C12 linear or branched alkyl group, a C2-C8 linear or branched alkyl group, a C2-C6 linear alkyl group, or a C3-C4 linear alkyl group.

4. The process of any one of claims 1-3, wherein the 1-alkyne and / or the 2-alkyne comprises 1 -hexyne, 2-hexyne, 2-heptyne, or a combination thereof.

5. The process of any one of claims 1-4, wherein the 1 -alkene comprises 1 -hexene.27118-200-9686. The process of any one of claims 1-5, wherein: the reaction mixture comprises the 1 -alkyne; and the 1 -alkyne comprises 1 -hexyne.

7. The process of any one of claims 1-6, wherein: the reaction mixture comprises the 2-alkyne; and the 2-alkyne comprises 2-hexyne.

8. The process of any one of claims 1-7, wherein step (a) is performed (or the dichloroalkane compound is formed) in the presence of a diluent.

9. The process of any one of claims 1-7, wherein step (a) is performed or the dichloroalkane compound is formed in the substantial absence of a diluent, for example, less than or equal to 25 wt. %, less than or equal to 10 wt. %, less than or equal to 5 wt. %, or less than or equal 2 wt. % of the diluent, based on total weight of the 1 -alkene and the diluent.

10. The process of any one of claims 1-9, wherein step (a) is performed or the di chloroalkane compound is formed at a temperature in a range from -30 to 500 °C, from -15 to 70 °C, from 15 to 400 °C, from -5 to 70 °C, from 5 to 70 °C, from 15 to 70 °C, or from 25 to 70 °C.

11. The process of any one of claims 1-10, wherein step (a) is performed or the dichloroalkane compound is formed at a pressure in a range from atmospheric to 500 psig, from atmospheric to 100 psig, from 10 to 250 psig, from 10 to 100 psig, or from 250 to 500 psig.

12. The process of any one of claims 1-11, wherein a molar ratio of l-alkene:chlorine (Ch) is in a range from 5: 1 to 1 :5, from 3: 1 to 1 :3, from 3: 1 to 1 : 1, from 2: 1 to 1:2, or from 2: 1 to 1 : 1.

13. The process of any one of claims 1-12, wherein the halide salt is present in step (a) and an amount of the halide salt in step (a), based on the 1 -alkene, is from 0. 1 to 10 wt. %, from 0.5 to 5 wt. %, from 0.5 to 2.5 wt. %, from 1 to 10 wt. %, or from 1 to 5 wt. %.28118-200-96814. The process of any one of claims 1-13, wherein the halide salt is present in step (a) and the halide salt comprises a fluoride salt, a chloride salt, a bromide salt, an iodide salt, or a combination thereof.

15. The process of any one of claims 1-14, wherein the halide salt is present in step (a) and the halide salt comprises a C15+ quaternary ammonium salt, a C19+ quaternary ammonium salt, or a C25+ quaternary' ammonium salt.

16. The process of any one of claims 1-15, wherein the halide salt is present in step (a) and the halide salt comprises NaCl, tetrabutylammonium chloride, tributylhexadecyl phosphonium chloride, trioctylmethylammonium chloride, a methyltrialkyl(C8-Cio) ammonium chloride, or a combination thereof.

17. The process of any one of claims 1-16, wherein an overall conversion of the 1 -alkene in step (a) is at least 80 wt. %, at least 85 wt. %, at least 90 wt. %, at least 95 wt. %, at least 98 wt. %, or at least 99 wt. %.

18. The process of any one of claims 1-17, wherein a molar yield of the di chloroalkane compound in step (a), based on the 1 -alkene in step (a), is at least 50 mol %, at least 60 mol %, at least 75 mol %, at least 80 mol %, at least 85 mol %, at least 90 mol %, at least 95 mol %, or at least 98 mol %.

19. The process of any one of claims 1-18 further comprising a step of isolating unreacted chlorine gas from the dichloroalkane compound in step (a), for example, using any suitable gas-liquid separation technique.

20. The process of claim 19, w herein the unreacted chlorine gas is recycled into step (a), for example, to react with the 1 -alkene.

21. The process of any one of claims 1-20, further comprising a step of isolating unreacted 1 -alkene from the dichloroalkane compound in step (a), for example, using any suitable separation technique.29118-200-96822. The process of claim 21, wherein the unreacted 1 -alkene is recycled into step (a), for example, to react with the chlorine.

23. The process of any one of claims 1-22, wherein step (b) is performed.

24. The process of any one of claims 1-23, wherein the catalyst in step (b) comprises a solid basic catalyst, alumina, activated carbon, or any combination thereof.

25. The process of any one of claims 1-24, wherein step (b) is performed or the chloroalkene compound is formed at a temperature in a range from 25 to 500 °C, from 100 to 500 °C, from 100 to 400 °C, from 150 to 450 °C, or from 250 to 400 °C.

26. The process of any one of claims 1-25, wherein an amount of the catalyst in step (b), based on the 1 ,2-dichloroalkane compound, is from 0.1 to 20 wt. %, from 0.2 to 15 wt. %, from 0.5 to 12 wt. %, from 1 to 12 wt. %, or from 1 to 8 wt. %.

27. The process of any one of claims 1-26, wherein step (b) is performed or the chloroalkene compound is formed at a pressure in a range from atmospheric to 500 psig, from atmospheric to 100 psig, from 10 to 250 psig, from 10 to 100 psig, or from 250 to 500 psig.

28. The process of any one of claims 1-27, wherein the base in step (c) comprises an alkali metal oxide, an alkali metal hydroxide, an alkali metal alkoxide, an alkali metal amide, an alkali metal hydride, an alkaline earth metal oxide, an alkaline earth metal hydroxide, an alkaline earth metal alkoxide, an alkaline earth metal amide, an alkaline earth metal hydride, or any combination thereof.

29. The process of any one of claims 1-28, wherein the base in step (c) comprises sodium hydroxide, potassium hydroxide, potassium t-butoxide, sodium amide, sodium t-butoxide, sodium butoxide, cesium hydroxide, methyl lithium, n-butyl lithium, sec-butyl lithium, tertbutyl lithium, n-hexyl lithium, calcium hydroxide, magnesium hydroxide, or any combination thereof.30118-200-96830. The process of any one of claims 1-29, wherein the reaction mixture further comprises an alkali metal salt and / or the alkaline earth metal salt, for example, LiCl, NaCl, KC1, CsCl, or a combination thereof.

31. The process of any one of claims 1-30, wherein the phase transfer catalyst comprises an alcohol, a diol, a glycol, a polyol, an ether, a glyme, a mono-glyme, an ammonium salt, a phosphonium salt, or a combination thereof.

32. The process of any one of claims 1-31, wherein the phase transfer catalyst comprises a C15+ quaternary ammonium salt, a C19+ quaternary ammonium salt, or a C25+ quaternary' ammonium salt.

33. The process of any one of claims 1-32, wherein the phase transfer catalyst comprises a polyethylene glycol, methanol, ethanol, propanol, pinacol (2,3-dimethylbutane-2,3-diol), tetrabutyl ammonium chloride, tributylhexadecyl phosphonium chloride, trioctylmethylammonium chloride, a methyltrialkyl(C8-Cio) ammonium chloride, or a combination thereof.

34. The process of any one of claims 1-33, wherein the phase transfer catalyst comprises a lipophilic quaternary ammonium salt, a hydrophilic quaternary' ammonium salt, a lipophilic quaternary phosphonium salt, or a combination thereof.

35. The process of any' one of claims 1-34, wherein step (c) is performed or the reaction mixture is formed in the presence of a reaction medium.

36. The process of claim 35, wherein the reaction medium in step (c) comprises a protic solvent.

37. The process of claim 35 or 36, wherein the reaction medium in step (c) comprises a polar non-protic solvent.31118-200-96838. The process of any one of claims 35-37, wherein the reaction medium in step (c) comprises a non-polar solvent.

39. The process of any one of claims 35-38, wherein the reaction medium in step (c) comprises dimethylsulfoxide, isopropanol, ethanol, butanol, a (poly) ethylene glycol, a (poly) propylene glycol, dihydrolevoglucosenone, a glyme, a mono-glyme, an ether, a polyether, water, N-methylpyrrolidone, dimethylcarbonate, sulfolane, dimethylformamide, mineral oil, decalin, tetralin, toluene, cyclohexane, a diesel fuel, a PAO, an isoparaffin or a mixture of alkanes, or any combination thereof.

40. The process of any one of claims 1-39, wherein step (c) is performed or the reaction mixture is formed at a temperature in a range from 0 to 600 °C, from 20 to 250 °C, from 20 to 80 °C, from 50 to 250 °C, or from 50 to 100 °C.

41. The process of any one of claims 1-40, wherein an amount of the phase transfer catalyst in step (c), based on the 1 ,2-dichloroalkane compound and the chloroalkene compound, is from 0.1 to 20 wt. %, from 0.2 to 15 wt. %, from 0.5 to 8 wt. %, from 1 to 10 wt. %, or from 3 to 7 wt. %.

42. The process of any one of claims 1-41, wherein a molar equivalent ratio of the base to the 1 ,2-dichloroalkane compound and the chloroalkene compound is from 5: 1 to 1 :5, from 1.1 : 1 to 5: 1, from 1.2: 1 to 4: 1, from 1.5: 1 to 4: 1, from 1: 1 to 2: 1, or from 1.8: 1 to 2.6:1.

43. The process of any one of claims 1-42, wherein step (c) is performed or the reaction mixture is formed at any suitable pressure, for example, from atmospheric to 1000 psig, or any pressure sufficient to keep the reaction mixture in the liquid phase.

44. The process of any one of claims 1-43, wherein step (c) is performed or the reaction mixture is formed using reactive distillation, thereby allowing the 1 -alkyne and / or the 2- alkyne to be collected as it is being formed.32118-200-96845. The process of any one of claims 1-44, wherein a molar yield of the 1-alkyne in step (c), based on the 1 -alkene in step (a), is at least 75 mol %, at least 80 mol %, at least 85 mol %, at least 90 mol %, at least 95 mol %, or at least 98 mol %.

46. The process of any one of claims 1-44, wherein a molar yield of the 2- alkyne in step (c), based on the 1 -alkene in step (a), is at least 75 mol %, at least 80 mol %, at least 85 mol %, at least 90 mol %, at least 95 mol %, or at least 98 mol %.

47. The process of any one of claims 1-46, wherein the process further comprises the steps of contacting the reaction mixture with water to form a multiphase mixture; separating the 1-alkyne and / or the 2-alkyne and an optional reaction medium from the multiphase mixture, for example, using phase separation and / or decanting.

48. The process of any one of claims 1-47, wherein the process further comprises the steps of: contacting the reaction mixture with water and the 1 -alkene to form a multiphase mixture; separating the base, an optional alkali metal salt and / or alkaline earth metal salt, and the phase transfer catalyst based on solubility from the multiphase mixture, for example, using phase separation and / or decanting.

49. The process of claim 47 or 48, wherein the process further comprises a step of separating the alkali metal salt and / or the alkaline earth metal salt, residual base, and water from the multiphase mixture, for example, using phase separation and / or decanting.

50. The process of claim 49, wherein the method further comprising a step of subjecting the separated water and the alkali metal salt and / or the alkaline earth metal salt to a chloroalkali electrolysis process to produce Ch, f , and a metal compound, for example, a metal hydroxide such as NaOH.33118-200-96851. The process of any one of claims 1-50, wherein the process further comprises a step of isolating the 1 -alkyne and / or the 2-alkyne from the reaction medium or the reaction mixture to form an alkyne product, for example, using distillation or wiped film evaporation.

52. The process of any one of claims 1-51, wherein an overall molar yield of the 1 -alkyne and / or the 2-alkyne, based on the 1-alkene in step (a), is at least 60 mol %, at least 70 mol %, at least 80 mol %, at least 85 mol %, at least 90 mol %, or at least 92 mol %.

53. The process of claim 51 or 52, wherein the alkyne product has an allene content of less than or equal to 3 wt. %, less than or equal to 2 wt. %, less than or equal to 1 wt. %, less than or equal to 5000 ppm, less than or equal to 1000 ppm, less than or equal to 500 ppm, less than or equal to 250 ppm, less than or equal to 150 ppm, less than or equal to 100 ppm, less than or equal to 50 ppm, less than or equal to 25 ppm. or less than or equal to 10 ppm (by weight).

54. The process of any one of claims 51-53, wherein the alkyne product has a propargy l alcohol content or a ketone content of less than or equal to 250 ppm, less than or equal to 150 ppm. less than or equal to 100 ppm, less than or equal to 50 ppm. less than or equal to 25 ppm, or less than or equal to 10 ppm (by weight).

55. The process of any one of claims 51-54, wherein the alkyne product has a peroxide content of less than or equal to 2000 ppm. less than or equal to 1000 ppm, less than or equal to 500 ppm, less than or equal to 250 ppm, less than or equal to 150 ppm, less than or equal to 100 ppm, less than or equal to 50 ppm, less than or equal to 25 ppm, or less than or equal to 10 ppm (by weight).

56. The process of any one of claims 51-55, wherein the alkyne product has a vinylchi ori de content of less than or equal to 5000 ppm, less than or equal to 1000 ppm, less than or equal to 500 ppm, less than or equal to 250 ppm, less than or equal to 150 ppm, less than or equal to 100 ppm, less than or equal to 50 ppm, less than or equal to 25 ppm, or less than or equal to 10 ppm (by weight).

57. The process of any one of claims 51-56, wherein:34118-200-968the alkyne product comprises at least 70 wt. %, at least 85 wt. %, at least 90 wt. %, at least 92 wt. %, at least 95 wt. %, at least 97 wt. %, or at least 99 wt. % of 1 -hexyne, or 2- hexyne, or 2-heptyne; and / or the alkyne product comprises at least 10 ppm, at least 50 ppm, at least 100 ppm, at least 250 ppm, at least 500 ppm, at least 1000 ppm, or at least 5000 ppm (by weight) and less than or equal to 12 wt. %, less than or equal to 10 wt. %, less than or equal to 7 wt. %, less than or equal to 5 wt. %, less than or equal to 2 wt. %, or less than or equal to 1 wt. % of 1- hexene, or 1 -heptene, or C3-C20 1 -alkenes.

58. The alkyne product produced by the process of any one of claims 51-57.

59. The alkyne product of claim 58, wherein: the alkyne product comprises at least 70 wt. %, at least 85 wt. %, at least 90 wt. %, at least 92 wt. %, at least 95 wt. %, at least 97 wt. %, or at least 99 wt. % of 1 -hexyne, or 2- hexyne, or 2-heptyne; and / or the alkyne product comprises at least 10 ppm, at least 50 ppm, at least 100 ppm, at least 250 ppm, at least 500 ppm, at least 1000 ppm, or at least 5000 ppm (by weight) and less than or equal to 12 wt. %, less than or equal to 10 wt. %, less than or equal to 7 wt. %, less than or equal to 5 wt. %, less than or equal to 2 wt. %, or less than or equal to 1 wt. % of 1 - hexene, or 1 -heptene, or C3-C20 1 -alkenes.35118-200-968

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