WO2008057920A1

WO2008057920A1 - PROCESSES FOR THE HYDROGENATION OF α-β-UNSATURATED KETONES

Info

Publication number: WO2008057920A1
Application number: PCT/US2007/083303
Authority: WO
Inventors: John K. Roberg; Stephen E. Belmont; Yaping Zhong
Original assignee: Albemarle Corporation
Priority date: 2006-11-02
Filing date: 2007-11-01
Publication date: 2008-05-15

Abstract

The catalytic hydrogenation of α-β-unsaturated ketones R1-CH=CH-CO-R2 in which R1 and R2 independently of one another represent straight-chain or branched C1-C12-alkyl or C2-C12-hydroxyalkyl, straight-chain or branched C2-C12 alkenyl, C3-C8-cycloalkyl, C3-C8 cycloalkenyl, C7-C14-aralkyl or C6-C12-aryl, where at least one of R1 and R2 is monosubstituted to trisubstituted by halogen, to give the respective saturated ketones R11-CH2-CH2-CO-R12 in which R11 and R12 assume the meaning of R1 and R2 with the exception that alkenyl and cycloalkenyl are hydrogenated to the respective alkyl or cycloalky, wherein the process comprises preparing a composition consisting essentially of (i) the α-β-unsaturated ketones and water in amounts such that the wt% of the α-β-unsaturated ketones based on the total weight of the α-β-unsaturated ketones and the water is at least about 65 wt% (i) basic substance, (ii) Ni-containing catalyst, and (iii) organic sulphur compound.

Description

PROCESSES FOR THE HYDROGENATION OF α.β-UNSATURATED KETONES

BACKGROUND

[0001] US Patent 4,940,819 describes a process for the catalytic hydrogenation of α.β-unsaturated ketones R¹ -CH=CH-CO-R² in which R¹ and R² independently of one another represent straight-chain or branched Ci-Ci₂-alkyl or C₂-Ci₂-hydroxyalkyl, straight-chain or branched C₂-Ci₂-alkenyl, Ca-Ce-cycloalkyl, C₃-Ce-cycloalkenyl, C7-C₁₄-aralkyl or C₆-Ci₂-aryl, where at least one of R¹ and R² is monosubstituted to trisubstituted by halogen, to give the respective saturated ketones R¹¹-CH₂-CH₂-CO-R¹² in which R¹¹ and R¹² assume the meaning of R¹ and R² with the exception that alkenyl and cycloalkenyl are hydrogenated to the respective alkyl or cycloalkyl, which is characterized in that a Ni-containing catalyst is employed and that the reaction is carried out in the presence of an organic sulphur compound R³-S(=O)_n-R⁴ in which R³ and R⁴ independently of one another denote straight-chain or branched Ci-Ci_∑-alkyI, hydroxy-C₂-Ci₂-alkyl, carboxy-Ci-Ci₂-alkyl or phenyl, and furthermore R³ and R⁴ may together represent -CH=CH-CH=CH-, -(CH₂)₄-, -CH₂)_S-, -(CH₂)₂-S-(CH₂)₂- or -(CH2)₂-O-(CH₂)₂-, R⁴ may additionally denote hydrogen or CO-Ci-Ci₂-alkyl and n assumes the value 0 or 1. It is disclosed that the reaction medium employed can be alcohols, such as methanol, ethanol, isopropanol, butanol, aliphatic or aromatic hydrocarbons, such as toluene, xylene, cyclohexane, isooctane and the like, ethers, such as tetrahydrofuran, dioxane or methyl tert-butyl ether, esters, such as ethyl acetate and lastly the reaction product itself if it is liquid at the reaction temperature; and, further that a proportion of water (for example up to 20% by weight of the total reaction medium) does not interfere, particularly if the reaction medium is water-soluble.

[0002] In the examples provided in US Patent 4,940,819, the weight percent of the α.β-unsaturated ketones to be hydrogenated as to the total weight of the ketones and the reaction medium ranges from about 17 wt% (63 g of ketones; 300 g of tetrahydrofuran) to about 40 wt% (120 g of ketones; 180 g of methanol). [0003] In spite of the disclosure of US 4,940,819, and other known processes for the catalytic hydrogenation of such α.β-unsaturated ketones, a need remains for such processes that can be performed at lower costs. THE INVENTION

[0004] This invention meets the above-described need by providing processes for the catalytic hydrogenation of α,β-unsaturated ketones R¹-CH==CH-CO-R² in which R¹ and R² independently of one another represent straight-chain or branched Ci-Ci₂-alkyl or C₂-Ci₂-hydroxyalkyl, straight-chain or branched C₂-Ci₂-alkenyl, C3-C₈-cycloalkyl, C₃-C₈-cyc!oaikenyl, C₇-C₁₄-aralkyl or Ce-C^-aryl, where at least one of R¹ and R² is monosubstituted to trisubstituted by halogen, to give the respective saturated ketones R¹¹-CH₂-CH₂-CO-R¹² in which R¹¹ and R¹² assume the meaning of R¹ and R² with the exception that alkenyl and cycloalkenyl are hydrogenated to the respective alkyl or cycloalkyl, which is characterized in that the process comprises combining the α.β-unsaturated ketones and water in amounts such that the wt% of the α,β-unsaturated ketones based on the total weight of the α.β-unsaturated ketones and the water is at least about 65 wt%, and the hydrogenation is carried out in the presence of (i) basic substance, (ii) Ni-containing catalyst, and (iii) organic sulphur compound R³-S(=O)_n-R⁴ in which R³ and R⁴ independently of one another denote straight-chain or branched Ci-Ci₂-alkyl, hydroxy-C₂-Ci₂-alkyl, carboxy-Ci-Ci₂-alkyl or phenyl, and furthermore R³ and R⁴ may together represent -CH=CH-CH=CH-, -(CH₂),,-, -CH₂)S-, -(CH₂)₂-S-(CH₂)₂- or -(CH₂J₂-O-(CH₂J₂-, R⁴ may additionally denote hydrogen or CO-Ci-Ci₂-alkyl and n assumes the value 0 or 1.

[0005] We have discovered that by using water, the initial weight percent of the α.β-unsaturated ketones to be hydrogenated as to the total weight of the α.β-unsaturated ketones and the water can be about 65 wt% and greater, thus providing an advantageously high throughput and a corresponding reduction in raw material and waste disposal costs. In processes according to this invention, the primary purpose of the water is to adjust the polarity of the reaction composition. Processes according to this invention can be conducted neat, i.e., in the absence of the water.

[0006] As will be familiar to those skilled in the art, the terms "combined" and "combining" as used herein mean that the components that are "combined" or that one is "combining" are put into a container with each other. Likewise a "combination" of components means the components having been put together in a container. This invention also provides such compositions and methods wherein the composition is an activator composition. [0007] This invention is described in connection with specific embodiments. It is understood that this invention is not limited to any one of these specific embodiments.

α,β-Unsaturated Ketones

[0008] α,β-unsaturated ketones suitable for hydrogenating according to this invention include α,β-unsaturated ketones R¹-CH=CH-CO-R² in which R¹ and R² independently of one another represent straight-chain or branched Ci-Ci₂-alky or

C₂-Ci2-hydroxyalkyl, straight-chain or branched C₂-Ci₂-alkenyl, C₃-C₈-cycloalkyl,

C₃-Ca-cycloalkenyl, Cy-Cu-aralkyl or C₆-Ci₂-aryl, where at least one of R¹ and R² is monosubstituted to trisubstituted by halogen.

[0009] Straight-chain or branched Ci-Ci₂-alkyl can be, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, amyl, hexyl, octyl, decyl or dodecyl;

Ci-C₆-alkyl and Ci-C₄-alkyl are included. Hydroxyalkyl carries a hydroxyl group in any position, for example in the ω-position, and may furthermore be interrupted in the carbon chain by ether oxygen. Carboxy-alkyl carries a carboxyl group in any position, e.g., in the α- or ω-position. Carboxy-alkyl can be Ci-Ci₂-alky; Ci-Ce-alkyl and

Ci-C<r-alkyl are included.

[0010] Straight-chain or branched C₂-Ci₂-alkenyl can be, for example, vinyl, propenyl, butenyl, isobutenyl, pentenyl, hexenyl, octenyl, decenyl or dodecenyl;

C₂-C₆-alkenyl and C₂-C₄-alkenyl are included.

[0011] Cβ-Cβ-cycloalkyl can be, for example, cyclopropyl, cyclobutyl, cydopentyl, cyclohexyl, cycloheptyl or cyclooctyl, any of which can be substituted by one or two methyl or ethyl groups; substituted or unsubstituted cyclopropyl, cydopentyl or cyclohexyl are included.

[0012] C₃-Ce-cycloalkenyl can be, for example, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl or cyclooctenyl.

[0013] C₇-Ci₄-aralkyl can be, for example, benzyl, phenylethyl, naphthylmethyl, naphthylethyl, biphenyl-methyl or biphenyl-ethyl.

[0014] C₆-Ci₂-aryl can be, for example, phenyl, e.g., 4-chlorophenyl, or naphthyl or biphenyl.

[0015] At least one of R¹ and R² in the α.β-unsaturated ketone is monosubstituted to trisubstituted by halogen, such as fluorine, chlorine or bromine. In the case of multiple substitution, it is not required that each substitution be by the same type of halogen atom. For example, one substitution can be by fluorine and a second substitution by bromine.

[0016] Each R¹ or R² that is aromatic can furthermore carry one or two methyl or ethyl groups, or methoxy or ethoxy groups, and also the hydroxyl group.

[0017] α,β-unsaturated ketones R¹-CH=CH-CO-R² can be used in which

R¹ and R² independently of one another denote straight-chain or branched Ci-Ce-alkyl,

C₂-C₆-alkenyl, cyclopropyl, cyclopentyl, cyclohexyl, benzyl, phenylethyl or phenyl, where at least one of R¹ and R² represents phenyl and where furthermore at least one of R¹ and R² is monosubstituted to trisubstituted by halogen.

[0018] Further suitable α,β-unsaturated ketones are R¹-CH=CH-CO-R² in which R¹ denotes phenyl and R² denotes straight-chain or branched d-C₆-alkyl, C₂-C₆-alkenyl, cyclopropyl, benzyl or phenyl, where at least one of R¹ and R² is monosubstituted to trisubstituted by halogen.

[0019] Further ketones are 5-halophenyl-2,2-dimethylpent-4-en-3-ones, particularly 5-(4-chlorophenyl)-2,2-dimethyl-pent-4-en-3-one, and

6-halophenyl-3,3-dimethylhex-5-en-4-ones.

[0020] All α,β-unsaturated ketones are in each case distinguished by at least one substituent which is substituted by halogen.

[0021] The α,β-unsaturated ketones to be used can be prepared via aldol condensation, as will be familiar to those skilled in the art.

Water

[0022] Water used in processes of this invention may be from any suitable source of potable water.

Basic Substances

[0023] Basic substances useful in this invention can comprise sodium hydroxide, potassium hydroxide, calcium hydroxide (for example in the form of slaked lime), calcium oxide, potassium carbonate, sodium carbonate, sodium acetate, and/or organic amines. Suitable organic amines include aliphatic amines, such as triethylamine or tripropylamine, and heterocyclic amines. The basic substances may, if they are water-soluble, be used as aqueous solution or as solid. Ni-Containing Catalysts

[0024] Catalysts used according to this invention can be Ni-containing, such as Ni on supports, Ni in the form of elemental nickel sponge, Ni oxide, Raney nickel and others. Supports can be, for example, SiC>₂, AI₂O3, pumice, carbon and other supports known to those skilled in the art. However, Raney catalysts, such as Raney nickel, Raney nickel-iron, Raney nickel-cobalt or Raney nickel-iron-cobalt in anhydrous or even water-moist or reaction medium/solvent-moist form can be used.

Organic Sulphur Compounds

[0025] Processes according to this invention can be carried out in the presence of one or more organic sulphur compounds R¹³-S(=O)_n-R¹⁴, where R¹³ and R¹⁴ independently of one another denote alkyl, hydroxy-C₂-Ci₂~alkyl or carboxy-Ci-Ci2-alkyl, and where R¹⁴ additionally may denote CO-Ci-C₆-alkyl and n assumes the value 0 or 1.

[0026] Examples of such compounds are bis-(2-hydroxyethyl) sulphide, bis-(2-hydroxypropyl) sulphide, thiodiacetic acid and its alkali metal salts, thioanisole, thiodipropionic acid, its salts and its dimethyl ester, diphenyl sulphide, dithiane, thioxane, thiophene, benzothiazole, dimethyl sulphoxide, methyl ethyl sulphoxide and diethyl sulphoxide.

[0027] The addition of the organic sulphur compound can be carried out together with the catalyst, before the addition or after the addition of the catalyst. If the catalyst is reused repeatedly, the organic sulphur compound in general only needs to be added to the catalyst or to the reaction mixture on the first use. A subsequent addition of the organic sulphur compound is possible, but generally only necessary if fresh catalyst is added in place of somewhat consumed or exhausted catalyst.

Process Details

[0028] The process can be carried out either batchwise or continuously.

[0029] The process may furthermore be applied using either pure α,β-unsaturated ketones or crude α,β-unsaturated ketones, for example from the aldol condensation, in which such α.β-unsaturated ketones can be obtained from an aldehyde and a methyl ketone. [0030] The α,β-unsaturated ketones and water can be added in amounts such that the wt% of the α,β-unsaturated ketones based on the total weight of the α,β-unsaturated ketones and the water is at least about 65 wt%. [0031] The basic substance can be added in an amount from about 0.001 to about 0.025 parts by weight, e.g., about 0.002 to about 0.01 parts by weight, per part by total weight of the α,β-unsaturated ketones and the basic substance. [0032] The Ni-containing catalyst can be added in an amount from about 0.001 to about 0.1 parts by weight, e.g., about 0.003 to about 0.04 parts by weight, per part by total weight of the α,β-unsaturated ketones and the Ni-containing catalyst. [0033] The organic sulphur compound can be used in an amount from 0.0002 to about 0.1 parts by weight, for example about 0.0004 to about 0.075, or about 0.01 to about 0.05 parts by weight, per part by weight of the total weight of the α,β-unsaturated ketones and the organic sulphur compound.

[0034] In general, the process can be carried out such that the unsaturated alkyl ketone, the water, the basic substance, the Ni-coritaining catalyst, and the organic sulphur compound are added to the hydrogenator. The hydrogenation can be carried out at about 30⁰C to about 250⁰C, for example at about 50°C to about 140⁰C, and at an H₂ pressure of about 150 psi to about 1000 psi, for example about 400 psi to about 800 psi. The exothermic hydrogenation reaction can proceed for about 3 hours at about 100°C to greater than 99% conversion of the unsaturated alkyl ketone to saturated alkyl ketone in produced crude product, which also comprises trace amounts of amine hydrochloride. The crude product comprising saturated alkyl ketone can be filtered to remove Ni-containing catalyst; filtering methods and aids known to those skilled in the art can be used, e.g., filter/body aids can be used. After the Ni-containing catalyst is filtered, a basic substance at a pH of about 8 to about 14, such as sodium hydroxide, potassium hydroxide, calcium hydroxide (for example in the form of slaked lime), calcium oxide, potassium carbonate, sodium carbonate, sodium acetate, or mixtures thereof, can be added to the crude product to convert the amine hydrochloride to a chloride, e.g., inorganic chloride, metal chloride (such as sodium chloride), or the like, and an amine, e.g., triethylamine. Then water can be distilled out using means known to those skilled in the art. A benefit is that the saturated alkyl ketone product can be distilled without the need for an aqueous wash to remove salts. The saturated alkyl ketone can then be distilled, using one or more distillation columns, e.g., two distillation columns. Continuous distillation can be used. [0035] A process according to this invention can comprise preparing a composition consisting essentially of (i) the α,β-unsaturated ketones and water in amounts such that the wt% of the α,β-unsaturated ketones based on the total weight of the α,β-unsaturated ketones and the water is at least about 65 wt%, (ii) basic substance, (iii) Ni-containing catalyst and (iv) organic sulphur compound R³-S(=O)_n-R⁴ in which: R³ and R⁴ independently of one another denote straight-chain or branched Ci-Ci₂-alkyl, hydroxy-C₂-Ci₂-alkyl, carboxy-Ci-Ci₂-alkyl or phenyl, and furthermore; R³ and R⁴ may together represent -CH=CH-CH=CH-, -(CH₂J₄-, -CH₂)₅-, -(CH₂)₂-S-(CH₂)₂- or -(CH₂)₂-O-(CH₂)₂-, R⁴ may additionally denote hydrogen or CO-Ci-Ci₂-alkyl and n assumes the value 0 or 1.

EXAMPLE

[0036] 1-(4-chlorophenyl)-4,4-dimethylpent-1-en-3-one (265 g), water (50 g), 2,2'-thiodiethanol (1.6 g), Raney nickel 2800 (10 g), and triethylamine (2.5 g) were added to a 1-L autoclave in a purgebox. After purging with nitrogen and hydrogen, the autoclave was pressured to 400 psig H₂ and heated to 100⁰C, with 1850 RPM agitation. After reaching 100⁰C₁ the pressure was increased to 700 psig and periodically repressured to maintain 700 psig H₂. After 2 hours, there was a 92.8% conversion, and the temperature was increased to 130⁰C. After 1 hour at 130°C, there was a 99.4% conversion, and the reaction was cooled to 25⁰C and depressured. After purging with nitrogen, the Raney nickel was filtered off, and the autoclave and solids were washed with water (90 mL).

[0037] 1-(4-chlorophenyl)-4,4-dimethylpent-1-en-3-one (265 g), water (120 g), 2,2'-thiodiethanol (1.6 g), Raney nickel 2800 (10 g), and triethylamine (3.0 g) were added to a 1-L autoclave in a purgebox. After purging with nitrogen and hydrogen, the autoclave was pressured to 400 psig H₂ and heated to 130⁰C, with 1800 RPM agitation. After reaching 13O⁰C, the pressure was increased to 700 psig and periodically repressured to maintain 700 psig H₂. After 1 hour, there was a 99.9% conversion, and the reaction was cooled to 25⁰C and depressured. After purging with nitrogen, the Raney nickel was filtered off, and the autoclave and solids were washed with water (90 mL). [0038] It is to be understood that the reactants and components referred to by chemical name or formula anywhere in the specification or claims hereof, whether referred to in the singular or plural, are identified as they exist prior to being combined with or coming into contact with another substance referred to by chemical name or chemical type (e.g., another reactant, a reaction medium/solvent, or etc.). It matters not what chemical changes, transformations and/or reactions, if any, take place in the resulting mixture or solution or reaction medium as such changes, transformations and/or reactions are the natural result of bringing the specified reactants and/or components together under the conditions called for pursuant to this disclosure. Thus the reactants and components are identified as ingredients to be brought together in connection with performing a desired chemical reaction or in forming a mixture to be used in conducting a desired reaction. Accordingly, even though the claims hereinafter may refer to substances, components and/or ingredients in the present tense ("comprises", "is", etc.), the reference is to the substance, component or ingredient as it existed at the time just before it was first contacted, combined, blended or mixed with one or more other substances, components and/or ingredients in accordance with the present disclosure. Whatever transformations, if any, which occur in situ as a reaction is conducted is what the claim is intended to cover. Thus the fact that a substance, component or ingredient may have lost its original identity through a chemical reaction or transformation during the course of contacting, combining, blending or mixing operations, if conducted in accordance with this disclosure and with the application of common sense and the ordinary skill of a chemist, is thus wholly immaterial for an accurate understanding and appreciation of the true meaning and substance of this disclosure and the claims thereof.

[0039] While the present invention has been described in terms of one or more preferred embodiments, it is to be understood that other modifications may be made without departing from the scope of the invention, which is set forth in the claims below.

Claims

CLAIMSWe Claim:

1. A process for the catalytic hydrogenation of α,β-unsaturated ketones R¹ -CH=CH-CO-R² in which:

R¹ and R² independently of one another represent straight-chain or branched Ci-Ci₂-alkyl or C₂-Ci₂-hydroxyalkyl, straight-chain or branched C₂-Ci₂-alkenyl, C₃-Ce-cycloalkyl, Ce-Ce-cycloalkenyl, C₇-Ci₄-aralkyl or Ce-C^-aryl, where at least one of R¹ and R² is monosubstituted to trisubstituted by halogen, to give saturated ketones R^-CH₂-CH₂-CO-R¹² in which:

R¹¹ and R¹² assume the meaning of R¹ and R², respectively, with the exception that alkenyl and cycloalkenyl are hydrogenated to the respective alkyl or cycloalkyl, wherein the process comprises combining at least the α,β-unsaturated ketones and water in amounts such that the wt% of the α,β-unsaturated ketones based on the total weight of the α,β-unsaturated ketones and the water is at least about 65 wt%, and the hydrogenation is carried out in the presence of (i) basic substance, (ii) Ni-containing catalyst and (iii) organic sulphur compound R³-S(=O)_n-R⁴ in which:

R³ and R⁴ independently of one another denote straight-chain or branched Ci-Ci₂-alkyl, hydroxy-C₂-Ci₂-alkyl, carboxy-Ci-Ci₂-alkyl or phenyl, and furthermore; R³ and R⁴ may together represent -CH=CH-CH=CH-, -(CH₂J₄-, -CH₂)_S-, -(CH₂)₂-S-(CH₂)₂- or -(CH₂)₂-O-(CH₂)₂- R⁴ may additionally denote hydrogen or CO-Ci-C-ι₂-alkyl and n assumes the value O or 1.

2. A process for the catalytic hydrogenation of α,β-unsaturated ketones R¹-CH=CH-C0-R² in which:

R¹ and R² independently of one another represent straight-chain or branched Ci-Ci₂-alkyl or C₂-Ci₂-hydroxyalkyl, straight-chain or branched C₂-Ci₂-alkenyl, C₃-Ce-cycloalkyl, C₃-Ce-cycloalkenyl, Cy-Cu-aralkyl or C₆-Ci₂-aryl, where at least one of R¹ and R² is monosubstituted to trisubstituted by halogen, to give saturated ketones R¹¹-CH₂-CH₂-CO-R¹² in which: R¹¹ and R¹² assume the meaning of R¹ and R², respectively, with the exception that alkenyl and cycloalkenyl are hydrogenated to the respective alkyl or cycloalkyl, wherein the process comprises preparing a composition consisting essentially of (i) the α,β-unsaturated ketones and water in amounts such that the wt% of the α,β-unsaturated ketones based on the total weight of the α,β-unsaturated ketones and the water is at least about 65 wt%, (ii) basic substance, (iii) Ni-containing catalyst and (iv) organic sulphur compound R³-S(=O)_n-R⁴ in which:

R³ and R⁴ independently of one another denote straight-chain or branched Ci-Ci₂-alkyl, hydroxy-C₂-Ci₂-alkyl, carboxy-Ci-Ci2-alkyl or phenyl, and furthermore; R³ and R⁴ may together represent -CH=CH-CH=CH-, -(CH₂J₄-, -CH₂)S-, -(CHz)₂-S-(CH₂)Z- or -(CH₂)₂-O-(CH₂)₂- R⁴ may additionally denote hydrogen or CO-Ci-Ci_∑-alkyI and n assumes the value 0 or 1.