Method for producing aliphatic aldehydes

Abstract

This invention provides a method for producing aliphatic aldehydes in high yield by oxidizing aliphatic primary alcohols having four or more carbon atoms. [Solution] A method for producing an aliphatic aldehyde, comprising the step of oxidizing an aliphatic primary alcohol having 4 or more carbon atoms with molecular oxygen in the presence of a phenol derivative and a metal-supported catalyst, wherein the metal-supported catalyst includes a metal supported on an inorganic carrier. A method for producing an aliphatic aldehyde, wherein the phenol derivative is a compound represented by general formula (I). JPEG2026104779000037.jpg27159

Description

[Technical Field]

[0001] This invention relates to a method for producing aliphatic aldehydes. [Background technology]

[0002] Conventionally, a method for producing carbonyl compounds has been known in which alcohols are oxidized in the presence of a metal catalyst to obtain carbonyl compounds.

[0003] For example, Patent Document 1 discloses a paper catalyst structure containing metal oxide fibers, alumina, and ruthenium. In this paper catalyst structure, a coating layer containing γ-structured alumina is formed on the surface of the metal oxide fibers, and ruthenium is held by the coating layer containing γ-structured alumina. This paper catalyst structure has been reported to have high catalytic activity and be suitable as an oxidation catalyst for alcohols.

[0004] Patent Document 2 discloses a method for producing carbonyl compounds, characterized by oxidizing a specific alcohol in the presence of a catalyst in which at least one metal selected from ruthenium and platinum is supported on an activated carbon carrier, and oxygen, to produce a carbonyl compound consisting of an aldehyde compound or a ketone compound. It has been reported that this method allows for the production of carbonyl compounds from various alcohols in higher yields.

[0005] Patent Document 3 reports an oxidation catalyst system composed of (A) a ruthenium compound and (B) dioxybenzenes or their oxidized counterparts. This method is reported to enable the high-yield oxidation of alcohols with molecular oxygen using only a small amount of catalyst. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2014-108393 [Patent Document 2] Japanese Patent Publication No. 2010-202555 [Patent Document 3] Japanese Patent Application Publication No. 11-226417 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, while the methods described in Patent Documents 1 and 2 are suitable for oxidizing aromatic alcohols and aliphatic secondary alcohols from a reactivity standpoint, they are not necessarily suitable for oxidizing aliphatic primary alcohols. Furthermore, the method described in Patent Document 3 requires a specific crosslinking polymer, which is not considered convenient.

[0008] Therefore, the present invention aims to provide a method for producing aliphatic aldehydes in high yield by oxidizing aliphatic primary alcohols. [Means for solving the problem]

[0009] The present invention relates to a method for producing aliphatic aldehydes, comprising the step of oxidizing an aliphatic primary alcohol having 4 or more carbon atoms with molecular oxygen in the presence of a phenol derivative and a metal-supported catalyst, The metal-supported catalyst includes a metal supported on an inorganic support, The present invention relates to a method for producing an aliphatic aldehyde, wherein the phenol derivative is a compound represented by general formula (I).

[0010] [ka]

[0011] During the ceremony, R 1 This is a hydrocarbon group, hydroxyl group, or alkoxy group which may contain one or more heteroatoms selected from the group consisting of oxygen atoms and nitrogen atoms. R 2 is a hydrogen atom or a linear or branched alkyl group. R 3 and R 4is, independently of each other, a hydrogen atom, a linear or branched alkyl group, or a cycloalkyl group which may be substituted with an alkyl group, or R 3 is a group represented by the formula (x), and R 4 is a hydrogen atom, a linear or branched alkyl group, or a cycloalkyl group which may be substituted with an alkyl group, and provided that the case where R 3 and R 4 are simultaneously hydrogen atoms is excluded.

[0012]

Chemical Formula

[0013] [In the formula, R 51 has the same definition as R 1 , R 52 has the same definition as R 2 , and R 54 has the same definition as R 4 . * indicates the bonding position.]

Advantages of the Invention

[0014] The method of the present invention has the advantage that an aliphatic aldehyde can be produced in good yield by oxidizing an aliphatic primary alcohol having 4 or more carbon atoms (hereinafter, also simply referred to as aliphatic primary alcohol) with molecular oxygen.

Embodiments for Carrying Out the Invention

[0015] The present inventors have found that an aliphatic aldehyde can be produced in good yield by oxidizing an aliphatic primary alcohol having 4 or more carbon atoms with molecular oxygen in the presence of a phenolic derivative of a compound represented by the general formula (I) and a metal-supported catalyst containing a metal supported on an inorganic carrier, and have completed the present invention.

[0016] The reason why aliphatic aldehydes can be produced in such high yield is presumed to be that, after the metal supported on the inorganic support is oxidized by oxygen, the metal is activated by binding with the phenol derivative, and then the aliphatic primary alcohol having 4 or more carbon atoms is oxidized to an aldehyde by the metal, while the phenol derivative can be quickly released.

[0017] [Method for producing aliphatic aldehydes] The present invention relates to a method for producing aliphatic aldehydes, comprising the step of oxidizing an aliphatic primary alcohol having 4 or more carbon atoms with molecular oxygen in the presence of a phenol derivative and a metal-supported catalyst, The metal-supported catalyst includes a metal supported on an inorganic support, The present invention relates to a method for producing an aliphatic aldehyde, wherein the phenol derivative is a compound represented by general formula (I).

[0018] [ka]

[0019] During the ceremony, R 1 This is a hydrocarbon group, hydroxyl group, or alkoxy group which may contain one or more heteroatoms selected from the group consisting of oxygen atoms and nitrogen atoms. R 2 is a hydrogen atom or a linear or branched alkyl group. R 3 and R 4 These are, independently of each other, a hydrogen atom, a linear or branched alkyl group, or a cycloalkyl group which may be substituted with an alkyl group, or R 3 The base is represented by equation (x), and R 4 However, it is a hydrogen atom, a linear or branched alkyl group, or a cycloalkyl group which may be substituted with an alkyl group. However, R 3 and R 4 Except when both are hydrogen atoms.

[0020] [ka]

[0021] [In the formula, R 51 is R 1 This is the same definition as R 52 is R 2 This is the same definition as R 54 is R 4 This is the same definition as above. * indicates the joining position.

[0022] <Aliphatic primary alcohols with 4 or more carbon atoms> In the present invention, the aliphatic primary alcohol having 4 or more carbon atoms may be linear or branched, and may be saturated or unsaturated. From the viewpoint of high reactivity in a short time, the aliphatic primary alcohol is preferably a linear saturated primary alcohol, and more preferably a linear saturated primary alcohol having 8 to 14 carbon atoms.

[0023] From the viewpoint of reactivity, the number of carbon atoms in the aliphatic primary alcohol is preferably 4 or more, more preferably 6 or more, even more preferably 7 or more, and even more preferably 8 or more. Similarly, it is preferably 30 or less, more preferably 22 or less, even more preferably 14 or less, and even more preferably 12 or less. From the viewpoint of reactivity, the number of carbon atoms in the aliphatic primary alcohol is preferably 4 to 30, more preferably 6 to 22, even more preferably 6 to 14, even more preferably 8 to 14, and even more preferably 8 to 12.

[0024] Specifically, the aliphatic primary alcohols include: C4 alcohols such as n-butyl alcohol and iso-butyl alcohol; C6 alcohols such as hexyl alcohol and isohexyl alcohol; C8 alcohols such as n-octyl alcohol (octanol), isooctyl alcohol, and 2-ethylhexyl alcohol; C9 alcohols such as n-nonyl alcohol, isononyl alcohol, and 3,5,5-trimethylhexyl alcohol; C10 alcohols such as n-decyl alcohol, 3,7-dimethyloctyl alcohol, and 2-propylheptyl alcohol; and n-undecyl alcohol. Examples include C11 alcohols such as kohl and 2-methyldecanol; C12 alcohols such as n-dodecyl alcohol (lauryl alcohol), 2-methylundecanol, and 2-butyloctanol; C14 alcohols such as myristyl alcohol (1-tetradecanol); C18 alcohols such as hexadecyl alcohols, oleyl alcohol, and stearyl alcohol; and behenyl alcohol, eicosyl alcohols, geraniol, nerol, citronellol, cyclopentylmethanol, cyclopentenylmethanol, cyclohexylmethanol, and cyclohexenylmethanol. The aliphatic primary alcohol is preferably an aliphatic linear saturated primary alcohol with 4 to 30 carbon atoms, more preferably 6 to 22, even more preferably 6 to 14, even more preferably 8 to 14, and even more preferably 8 to 12.

[0025] <Phenol derivatives> The phenol derivative in the manufacturing method of the present invention is a compound represented by the following general formula (I).

[0026] [ka]

[0027] During the ceremony, R 1This is a hydrocarbon group, hydroxyl group, or alkoxy group which may contain one or more heteroatoms selected from the group consisting of oxygen atoms and nitrogen atoms. R 2 is a hydrogen atom or a linear or branched alkyl group. R 3 and R 4 These are, independently of each other, a hydrogen atom, a linear or branched alkyl group, or a cycloalkyl group which may be substituted with an alkyl group, or R 3 The base is represented by equation (x), and R 4 However, it is a hydrogen atom, a linear or branched alkyl group, or a cycloalkyl group which may be substituted with an alkyl group. However, R 3 and R 4 Except when both are hydrogen atoms.

[0028] [ka]

[0029] [In the formula, R 51 is R 1 This is the same definition as R 52 is R 2 This is the same definition as R 54 is R 4 This is the same definition as above. * indicates the joining position.

[0030] In the present invention, the R 1 The hydrocarbon group may contain one or more heteroatoms selected from the group consisting of oxygen and nitrogen atoms, and the number of carbon atoms is preferably 1 to 50, more preferably 1 to 30, more preferably 1 to 10, and even more preferably 1 to 5. The hydrocarbon group may be a linear or branched alkyl group, aryl group, alkylaryl group, arylalkyl group, or cycloalkyl group.

[0031] Hydrocarbon groups that may contain heteroatoms may include hydrocarbon groups containing heteroatoms by substituents such as ether groups, carbonyl groups, ester groups, hydroxyl groups, nitro groups, alkoxy groups, phenoxy groups, acyloxy groups, and triazine groups. Specifically, hydrocarbon groups that may contain one or more heteroatoms selected from the group consisting of oxygen and nitrogen atoms can be represented by the following formulas (i) to (ix) (wherein * indicates the bond position).

[0032] [ka]

[0033] [ka]

[0034] [ka]

[0035] [ka]

[0036] The aforementioned R 1 The alkyl group is a linear or branched alkyl group, and the number of carbon atoms of the alkyl group is preferably 1 to 8, more preferably 1 to 5, and even more preferably 1 to 3. Specifically, examples include methyl group; ethyl group; n-propyl group, i-propyl group; n-butyl group, i-butyl group, sec-butyl group, t-butyl group; n-pentyl group, i-pentyl group, sec-pentyl group, t-pentyl group; 2-methylbutyl group; heptyl group; octyl group; and 2-ethylhexyl group.

[0037] The aforementioned R 1 Examples of aryl groups include those with 6 to 10 carbon atoms, such as the phenyl group and the naphthyl group. Note that the term "naphthyl group" includes both 1-naphthyl and 2-naphthyl groups.

[0038] The aforementioned R 1 The alkylaryl group can be one in which the alkyl group is substituted on the aryl group, for example, a methylphenyl group, an ethylphenyl group, and so on.

[0039] The aforementioned R 1 The arylalkyl group can be one in which the aryl group is substituted on the alkyl group, for example, a benzyl group (phenylmethyl group), a phenethyl group (phenylethyl group), and the like.

[0040] The aforementioned R 1 Examples of alkoxy groups include alkoxy groups having 1 to 5 carbon atoms, preferably alkoxy groups having 1 to 3 carbon atoms. Examples of alkoxy groups having 1 to 5 carbon atoms include C1 alkyl groups such as methoxy groups; C2 alkoxy groups such as ethoxy groups; C3 alkoxy groups such as n-propyloxy groups and i-propyloxy groups; C4 alkoxy groups such as n-butoxy groups, i-butoxy groups, sec-butoxy groups, and t-butoxy groups; and C5 alkoxy groups such as n-pentyloxy groups, i-pentyloxy groups, sec-pentyloxy groups, t-pentyloxy groups, and 2-methylbutyloxy groups.

[0041] R 2 is a hydrogen atom or a linear or branched alkyl group. The number of carbon atoms in the alkyl group is preferably 1 to 8, more preferably 1 to 5, and even more preferably 1 to 3. Specifically, examples include methyl group; ethyl group; n-propyl group, i-propyl group; n-butyl group, i-butyl group, sec-butyl group, t-butyl group; n-pentyl group, i-pentyl group, sec-pentyl group, t-pentyl group; 2-methylbutyl group; heptyl group; octyl group; and 2-ethylhexyl group.

[0042] R 3 and R 4These are, independently of each other, a hydrogen atom, a linear or branched alkyl group, a cycloalkyl group which may be substituted with an alkyl group, or R 3 The base is represented by equation (x), and R 4 However, R is a hydrogen atom, a linear or branched alkyl group, or a cycloalkyl group which may be substituted with an alkyl group, provided that R 3 and R 4 Except when both are hydrogen atoms.

[0043] R 3 and R 4 The number of carbon atoms in the alkyl group is preferably 1 to 8, more preferably 1 to 5, and even more preferably 1 to 3. Specifically, the above-mentioned examples are available.

[0044] R 3 and R 4 The alkyl group of the cycloalkyl group, which may be substituted with an alkyl group, preferably has 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms. Specifically, the above-mentioned examples are included.

[0045] R 3 and R 4 The cycloalkyl group preferably has 3 to 10 carbon atoms, more preferably 6 carbon atoms. Examples include cycloalkyl groups with 3 carbon atoms such as cyclopropyl; cycloalkyl groups with 4 carbon atoms such as cyclobutyl; cycloalkyl groups with 5 carbon atoms such as cyclopentyl; and cycloalkyl groups with 6 carbon atoms such as cyclohexyl.

[0046] R 3 and R 4 A specific example of a cycloalkyl group that may be substituted with an alkyl group is the 1-methylcyclohexyl group.

[0047] R 3 and R 4The number of carbon atoms in the branched alkyl group is preferably 3 to 8, more preferably 3 to 5. Examples include i-propyl group; i-butyl group, sec-butyl group, t-butyl group; n-pentyl group; i-pentyl group, sec-pentyl group, t-pentyl group, 2-methylbutyl group.

[0048] R 3 and R 4 At least one of these preferably contains a branched alkyl group having 3 to 8 carbon atoms or a cycloalkyl group which may be substituted with an alkyl group, and more preferably contains a branched alkyl group having 3 to 8 carbon atoms.

[0049] Also, R 3 and R 4 At least one of them is a branched alkyl group having 3 to 8 carbon atoms, from the viewpoint of producing aliphatic aldehydes in good yield, and the other is preferably a hydrogen atom, R 3 and R 4 Both are preferably branched alkyl groups.

[0050] A preferred embodiment is one that, from the viewpoint of producing an aliphatic aldehyde in general formula (I) in good yield, R 1 This is an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms, or a group represented by formula (iii), formula (iv), formula (v), formula (vi), formula (vii), formula (viii), or formula (ix) (wherein * indicates the bond position), R 2 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R 3 and R 4 These are, independently of each other, a hydrogen atom, a branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms which may be substituted with an alkyl group, or R 3 The group is represented by formula (ii) (where * indicates the bond position), and R 4However, R is a hydrogen atom, a linear or branched alkyl group, or a cycloalkyl group which may be substituted with an alkyl group, provided that R 3 and R 4 It is preferable to exclude the case where both are hydrogen atoms, specifically CBP(2,2'-methylenebis[6-(1-methylcyclohexyl)-p-cresol]).

[0051] [ka]

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] A more preferred embodiment is one in which, from the viewpoint of producing an aliphatic aldehyde in general formula (I) in good yield, R 1 This is an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. R 2 It is a hydrogen atom, R 3 and R 4 These are, independently of each other, a hydrogen atom and a branched alkyl group having 3 to 8 carbon atoms. However, R 3 and R 4 It is preferable to exclude the case where both are hydrogen atoms.

[0056] A more preferred embodiment is one in which, from the viewpoint of producing an aliphatic aldehyde in general formula (I) in good yield, R 1 This is an alkyl group having 1 to 5 carbon atoms. R 2is a hydrogen atom, R 3 and R 4 are, independently of each other, branched alkyl groups having 3 to 8 carbon atoms.

[0057] More preferably, in general formula (I), from the viewpoint of producing an aliphatic aldehyde in good yield, R 1 is a methyl group, R 2 is a hydrogen atom, R 3 and R 4 are more preferably branched alkyl groups having 4 carbon atoms.

[0058] Examples of the compound represented by general formula (I) include the following compounds.

[0059]

Table 1

[0060] The compound represented by general formula (I) includes, for example, the compound represented by the following formula (II) or formula (III).

[0061]

Chemical formula

[0062] In formula (II), from the viewpoint of producing an aliphatic aldehyde in good yield, R 12 and R 14 are, independently of each other, branched alkyl groups. In the above formula (II), R 12 and R 14 are, independently of each other, preferably branched alkyl groups having 3 to 8 carbon atoms.

[0063] Examples of the compound represented by general formula (II) include 2,5 - di - tert - butylhydroquinone (DBH).

[0064] [ka]

[0065] [ka]

[0066] [In the formula, R 21 It is an alkoxy group, R 23 It is a branched alkyl group.

[0067] In formula (III) above, from the viewpoint of producing aliphatic aldehydes in good yield, R 21 This is an alkoxy group having 1 to 5 carbon atoms. R 23 It is preferably a branched alkyl group having 3 to 8 carbon atoms. R 21 This is an alkoxy group having 1 to 3 carbon atoms. R 23 It is more preferable that the element is a branched alkyl group having 3 to 6 carbon atoms.

[0068] Compounds represented by general formula (III) include, for example, 3-tert-butyl-4-hydroxyanisole (BHA).

[0069] [ka]

[0070] <Metal-supported catalyst> In the present invention, the metal-supported catalyst includes a metal supported on an inorganic support. From the viewpoint of aliphatic aldehyde yield, the metal can be a platinum group element such as ruthenium (Ru), palladium (Pd), rhodium (Rh), or platinum (Pt), with ruthenium being preferred. The inorganic support can be, for example, a porous oxide. The porous oxide can be one or more selected from the group consisting of alumina, titania, zirconia, silica, silica-alumina, magnesia, zeolite, and activated carbon. From the viewpoint of high activity and high selectivity, the support can be alumina, activated carbon, titania, silica-alumina, or zeolite, with alumina and activated carbon being more preferred. In the present invention, the porous oxide can be used alone or in combination of two or more types.

[0071] In the present invention, the metal-supported catalyst preferably has a surface area of ​​60 m² per unit mass of metal. 2 The value is 1 / g or more. A large surface area per unit mass of metal means that the particle size of the metal is small, and the metal is widely dispersed in the carrier, i.e., dispersed in a carrier with a large pore volume. The surface area per unit mass of metal can be measured by the pulse method, especially the CO pulse method.

[0072] From the viewpoint of increasing reactivity, the surface area per unit mass of the metal is preferably 60 m². 2 / g or more, comfortable 65m 2 / g or more, more preferably 70m 2 / g or more, comfortably 100m 2 / g or more, more preferably 130m 2 It is 1 / g or more, and from the same viewpoint, preferably 250m 2 / g or less, more preferably 200m 2 / g or less, more preferably 190m 2 / g or less, more preferably 180m 2 / g or less, more preferably 170m 2 It is less than / g. From the viewpoint of increasing reactivity, the surface area per unit mass of metal is preferably 60m². 2 / g or more 250m 2 / g or less, more preferably 65m 2 / g or more 250m 2 / g or less, more preferably 65m 2 / g or more 200m 2 / g or less, more preferably 70m 2 / g or more 200m 2 / g or less, more preferably 70m 2 / g or more 190m 2 / g or less, more preferably 70m 2 / g or more 180m 2 / g or less, more preferably 70m 2 / g or more 170m 2 / g or less, more preferably 100m 2 / g or more 170m 2 / g or less, more preferably 130m 2 / g or more 160m 2 It is less than / g.

[0073] The surface area per unit mass of a metal can be adjusted during catalyst preparation by increasing the amount of metal compound relative to the raw material carrier, or by using a carrier with a large surface area, i.e., a highly porous carrier. In this case, as will be described later, it is preferable to increase the mesopore volume by reducing the macropores of the carrier in order to increase both catalytic activity and the surface area per unit mass of the metal.

[0074] From the viewpoint of reactivity, the particle size of the metal is preferably 1 nm or larger, more preferably 2 nm or larger, and even more preferably 2.5 nm or larger. Similarly, from the same viewpoint, it is preferably 20 nm or smaller, more preferably 15 nm or smaller, and even more preferably 10 nm or smaller. This particle size can be determined by the method described in the examples.

[0075] The mesopore volume of the metal-supported catalyst can be measured by mercury porosimetry according to ASTM D4284-83. Specifically, the measurement is performed by filling a measurement cell containing the sample with mercury and pressurizing the inside of the cell. Then, the amount of mercury that enters is detected by a capacitance detector and the pore volume is measured. Alternatively, by modeling the pores as cylindrical, the pore distribution can be determined and the mesopore volume can be calculated. Catalysts having a mesopore volume of 0.15 mL / g or more are considered to have a pore size suitable for the reaction site of the oxidation reaction of the aliphatic primary alcohol.

[0076] When the metal of the metal-supported catalyst is ruthenium, the mesopore volume of the metal-supported catalyst is preferably 0.15 mL / g or more, preferably 0.2 mL / g or more, more preferably 0.25 mL / g or more, from the viewpoint of increasing the reactivity of aliphatic primary alcohols having 4 or more carbon atoms and suppressing the oxidation of aldehydes to carboxylic acids, and from the viewpoint of catalyst preparation, preferably 0.5 mL / g or less, more preferably 0.45 mL / g or less, and even more preferably 0.4 mL / g or less. When the metal of the metal-supported catalyst is ruthenium, the mesopore volume of the catalyst is preferably 0.15 mL / g or more and 0.5 mL / g or less, more preferably 0.2 mL / g or more and 0.5 mL / g or less, even more preferably 0.25 mL / g or more and 0.5 mL / g or less, even more preferably 0.25 mL / g or more and 0.5 mL / g or less, even more preferably 0.25 mL / g or more and 0.45 mL / g or less, and even more preferably 0.25 mL / g or more and 0.4 mL / g or less, from the viewpoint of increasing the reactivity of aliphatic primary alcohols having 4 or more carbon atoms and suppressing further oxidation of aldehydes to carboxylic acids, and from the viewpoint of catalyst adjustment.

[0077] The metal content in the metal-supported catalyst is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, relative to the entire catalyst, from the viewpoint of reactivity. Similarly, it is preferably 50% by mass or less, more preferably 30% by mass or less, even more preferably 10% by mass or less, and even more preferably less than 10% by mass. The metal content in the metal-supported catalyst is preferably 1% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 30% by mass or less, even more preferably 1% by mass or more and 10% by mass or less, even more preferably 1% by mass or more and less than 10% by mass, relative to the entire catalyst, from the viewpoint of reactivity.

[0078] <Method for manufacturing metal-supported catalysts> The metal-supported catalyst used in the present invention may be a commercially available metal-supported catalyst containing a metal supported on an inorganic support. Alternatively, such a metal-supported catalyst may be manufactured in accordance with known art or common technical knowledge. Examples of such manufacturing methods include impregnation methods in which a metal is impregnated into a support, and liquid-phase reduction methods in which a reducing agent is added.

[0079] An example of a method for producing a metal-supported catalyst used in the present invention, such as a ruthenium-supported catalyst, is described below. First, the porous oxide is added to a medium such as deionized water and suspended. Then, a solution of the ruthenium compound dissolved in an aqueous solvent such as deionized water is added to this suspension, and the mixture is heated while stirring as needed to adjust the temperature to about 20-95°C, preferably 40-80°C, to obtain a suspension containing the ruthenium compound. Examples of the ruthenium compound include ruthenium chloride, nitrate, formate, and ammonium salt.

[0080] Next, an alkali is added to the suspension containing the ruthenium compound to adjust the pH to 4-12, preferably 6-11, and hydrolysis is carried out, followed by aging to support the ruthenium component on a porous oxide. There are no particular restrictions on the type of alkali, but ammonia water, alkali metal carbonates such as sodium and potassium, hydroxides, etc., can be used. The time for adjusting the pH and aging is not particularly limited as long as sufficient time is provided for the ruthenium compound to hydrolyze.

[0081] Next, a reducing agent such as formaldehyde, hydrazine, or sodium borohydride is added to the reaction solution, and the mixture is heated as needed. After reduction treatment at a temperature of approximately 20-95°C, preferably 60-95°C, the solid-liquid separation is performed by filtration or the like. The obtained solid is thoroughly washed with water and then dried at a temperature of preferably 140°C or lower under atmospheric pressure or reduced pressure. The reducing agent may be used alone or in combination of two or more types. In order to effectively reduce the supported ruthenium component, the reducing agent is usually used in a ratio of approximately 1 to 5 molars, preferably 15 to 40 molars, relative to the ruthenium. The duration of the reduction treatment described above is not particularly limited, as long as sufficient time is available for the reduction reaction to proceed to the desired extent. The reduction procedure described above is not necessarily required. After supporting the ruthenium component by hydrolysis, solid-liquid separation may be performed, and the resulting solid material may be thoroughly washed with water and dried.

[0082] When ruthenium components are supported on porous oxides by hydrolysis as described above, it is not necessarily required to perform operations such as high-temperature calcination or high-temperature reduction under an inert gas atmosphere, which are usually carried out in impregnation methods, and the preparation of the catalyst is simple. The ruthenium-supported catalyst obtained in this manner contains ruthenium as metal in a proportion of approximately 1 to 5% by mass, more preferably 3 to 30% by mass, based on the total amount of catalyst including porous oxides, from the viewpoint of sufficient catalytic activity, selectivity, and economic efficiency. The ruthenium content in the catalyst can be measured by ICP emission spectrometry after the catalyst has been melted with ammonium bisulfate.

[0083] <Method for producing aliphatic aldehydes> The present invention's manufacturing method includes a step of oxidizing an aliphatic primary alcohol having 4 or more carbon atoms with molecular oxygen in the presence of a phenol derivative and a metal-supported catalyst.

[0084] In this process, the molar ratio of the phenol derivative to the metal (phenol derivative (mmol) / metal (mmol)) is preferably 0.7 or more, more preferably 0.9 or more, even more preferably 1.5 or more, preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less, from the viewpoint of aldehyde yield. The molar ratio of the phenol derivative to the metal (phenol derivative (mmol) / metal (mmol)) is preferably 0.7 or more and 10 or less, more preferably 0.9 or more and 5 or less, and even more preferably 1.5 or more and 3 or less, from the viewpoint of aldehyde yield.

[0085] In this process, the molar ratio of the phenol derivative to the aliphatic primary alcohol (phenol derivative (mmol) / aliphatic primary alcohol (mmol)) is preferably 0.005 or more, more preferably 0.01 or more, even more preferably 0.03 or more, preferably 3 or less, more preferably 1 or less, and even more preferably 0.3 or less, from the viewpoint of aldehyde yield. The molar ratio of the phenol derivative to the aliphatic primary alcohol (phenol derivative (mmol) / aliphatic primary alcohol (mmol)) is preferably 0.005 or more and 3 or less, more preferably 0.01 or more and 1 or less, and even more preferably 0.03 or more and 0.3 or less, from the viewpoint of aldehyde yield.

[0086] In this process, the molar ratio of metal to aliphatic primary alcohol having 4 or more carbon atoms (metal (mmol) / aliphatic primary alcohol having 4 or more carbon atoms (mmol)) is preferably 0.001 or higher, more preferably 0.005 or higher, and even more preferably 0.01 or higher from the viewpoint of aldehyde yield, and preferably 0.5 or lower, preferably 0.2 or lower, more preferably 0.1 or lower, more preferably 0.07 or lower, even more preferably 0.05 or lower, even more preferably 0.045 or lower, and even more preferably 0.04 or lower from the viewpoint of efficiency. From these viewpoints, preferably 0.001 to 0.5, preferably 0.001 to 0.2, more preferably 0.001 to 0.1, even more preferably 0.001 to 0.05, even more preferably 0.005 to 0.05, even more preferably 0.001 to 0.045, preferably 0.005 to 0.07, even more preferably 0.005 to 0.045, even more preferably 0.01 to 0.05, even more preferably 0.01 to 0.045, and even more preferably 0.01 to 0.04.

[0087] The molecular oxygen (referring to elemental molecular oxygen (oxygen gas); the same applies hereinafter) functions as an oxidizing agent in this step. This molecular oxygen is present in the reaction system of the present invention and only needs to be in contact with an aliphatic primary alcohol having 4 or more carbon atoms. Specifically, this step can be carried out in an atmospheric environment. Furthermore, it is preferable to carry out this step in an oxygen atmosphere because the oxidation reaction of aliphatic primary alcohols having 4 or more carbon atoms can be carried out in a higher yield. An oxygen atmosphere may include gases other than oxygen, such as air, and may be 100% oxygen, or it may include oxygen and an inert gas such as nitrogen, helium, or argon. In an oxygen atmosphere, the oxygen gas concentration is preferably 5% by volume or more, and more preferably 10% by volume or more. In an oxygen atmosphere, it is preferable to have a high concentration of oxygen, as a high concentration of oxygen can increase the reaction yield.

[0088] This step may be carried out in the presence of a solvent. The solvent is preferably one that can dissolve the aliphatic primary alcohol, such as water and organic solvents. Examples of such solvents include aromatic solvents such as toluene, liquid paraffin, and hydrocarbon solvents such as squalene. Among these, from the viewpoint of reaction efficiency, aromatic organic solvents having 6 to 40 carbon atoms are preferred. The solvent can be used alone or in combination of two or more.

[0089] In this process, the ratio of solvent (mL) to aliphatic primary alcohol (mmol) having 4 or more carbon atoms, i.e., solvent (mL) / aliphatic primary alcohol (mmol) having 4 or more carbon atoms, is preferably 0.01 or more, more preferably 0.05 or more, and even more preferably 0.1 or more, from the viewpoint of reactivity, and similarly, preferably 6 or less, more preferably 4 or less, and even more preferably 2 or less. The ratio of solvent to aliphatic primary alcohol having 4 or more carbon atoms is preferably 0.01 or more and 6 or less, more preferably 0.05 or more and 4 or less, and even more preferably 0.1 or more and 2 or less, from the viewpoint of reactivity.

[0090] The reaction temperature in this process is not particularly limited. When heating is used, the reaction temperature is preferably below the boiling point of the solvent used. From the viewpoint of reactivity, the reaction temperature is preferably 60°C or higher, more preferably 70°C or higher, and even more preferably 80°C or higher. From the viewpoint of productivity, it is preferably 200°C or lower, more preferably 180°C or lower, and even more preferably 170°C or lower. From the viewpoint of reactivity and productivity, the reaction temperature is preferably 60°C to 200°C, more preferably 70°C to 180°C, and even more preferably 80°C to 170°C.

[0091] The pressure used in this process is not limited, but it is preferable to perform it at atmospheric pressure or under reduced pressure.

[0092] The manufacturing method of the present invention is suitable not only for batch production but also for continuous flow production, as it can produce aldehydes in a short time and with high yield.

[0093] The present invention includes the following embodiments. [1] A method for producing an aliphatic aldehyde, comprising the step of oxidizing an aliphatic primary alcohol having 4 or more carbon atoms with molecular oxygen in the presence of a phenol derivative and a metal-supported catalyst, The metal-supported catalyst includes a metal supported on an inorganic support, A method for producing an aliphatic aldehyde, wherein the phenol derivative is a compound represented by general formula (I).

[0094] [ka]

[0095] During the ceremony, R 1 This is a hydrocarbon group, hydroxyl group, or alkoxy group which may contain one or more heteroatoms selected from the group consisting of oxygen atoms and nitrogen atoms. R 2 is a hydrogen atom or a linear or branched alkyl group. R 3 and R 4 These are, independently of each other, a hydrogen atom, a linear or branched alkyl group, or a cycloalkyl group which may be substituted with an alkyl group, or R 3 The base is represented by equation (x), and R 4 However, it is a hydrogen atom, a linear or branched alkyl group, or a cycloalkyl group which may be substituted with an alkyl group. However, R 3 and R 4 Except when both are hydrogen atoms.

[0096] [ka]

[0097] [In the formula, R 51 is R 1 This is the same definition as R 52 is R 2 This is the same definition as R 54is R 4 This is the same definition as [the previous definition]. In the formula, * indicates the bonding position.

[0098] [2] In the formula, R 3 and R 4 The method for producing the product according to [1], wherein at least one of the products comprises a branched alkyl group having 3 to 8 carbon atoms.

[0099] [3] In general formula (I), R 1 This is an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms, or a group represented by formula (iii), formula (iv), formula (v), formula (vi), formula (vii), formula (viii), or formula (ix) (wherein * indicates the bond position), R 2 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R 3 and R 4 These are, independently of each other, a hydrogen atom, a branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms which may be substituted with an alkyl group, or R 3 The group is represented by formula (ii) (where * indicates the bond position), and R 4 However, R is a hydrogen atom, a linear or branched alkyl group, or a cycloalkyl group which may be substituted with an alkyl group, provided that R 3 and R 4 The manufacturing method according to [1] or [2], except in the case where both are hydrogen atoms.

[0100] [ka]

[0101] [ka]

[0102] [ka]

[0103] [ka]

[0104] [4] In general formula (I), R 1 This is an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. R 2 It is a hydrogen atom, R 3 and R 4 These are, independently of each other, a hydrogen atom and a branched alkyl group having 3 to 8 carbon atoms, where R 3 and R 4 The manufacturing method according to any one of [1] to [3], except when both are hydrogen atoms.

[0105] [5] In general formula (I), R 1 This is an alkyl group having 1 to 5 carbon atoms. R 2 is a hydrogen atom, R 3 and R 4 The manufacturing method according to any one of [1] to [4], wherein each is a branched alkyl group having 3 to 8 carbon atoms, independently of the others.

[0106] [6] In general formula (I), R 1 It is a methyl group, R 2 is a hydrogen atom, R 3 and R 4 The manufacturing method according to any one of [1] to [5], wherein is a branched alkyl group having 4 carbon atoms.

[0107] [7] The manufacturing method according to any one of [1] to [6], wherein the metal comprises a platinum group element.

[0108] [8] The manufacturing method according to any one of [1] to [7], wherein the metal comprises ruthenium.

[0109] [9] The method for producing the inorganic support according to any one of [1] to [8], wherein the inorganic support comprises a porous oxide.

[0110]

[10] The manufacturing method according to any one of [1] to [9], wherein the porous oxide is one or more selected from the group consisting of alumina, titania, zirconia, silica, silicaalumina, magnesia, zeolite, and activated carbon.

[0111]

[11] The method for producing an aliphatic primary alcohol according to any one of [1] to

[10] , wherein the aliphatic primary alcohol is an aliphatic linear saturated primary alcohol, preferably an aliphatic linear saturated primary alcohol having 8 or more carbon atoms and 14 or fewer carbon atoms.

[0112]

[12] The method for producing the aliphatic primary alcohol according to any one of [1] to

[11] , wherein the number of carbon atoms in the aliphatic primary alcohol is 4 or more and 30 or less.

[0113]

[13] The manufacturing method according to any one of [1] to

[12] , wherein the aliphatic primary alcohol has 6 or more carbon atoms and 22 or less carbon atoms.

[0114]

[14] The manufacturing method according to any one of [1] to

[13] , wherein the aliphatic primary alcohol has 6 or more carbon atoms and 14 or less carbon atoms.

[0115]

[15] The manufacturing method according to any one of [1] to

[14] , wherein the molar ratio of the phenol derivative to the metal (phenol derivative (mmol) / the metal (mmol)) is 0.7 or more and 10 or less.

[0116]

[16] The manufacturing method according to any one of [1] to

[15] , wherein the molar ratio of the phenol derivative to the metal (phenol derivative (mmol) / the metal (mmol)) is 0.9 or more and 5 or less.

[0117]

[17] The manufacturing method according to any one of [1] to

[16] , wherein the molar ratio of the phenol derivative to the metal (phenol derivative (mmol) / the metal (mmol)) is 1.5 or more and 3 or less.

[0118]

[18] The manufacturing method according to any one of [1] to

[17] , wherein the molar ratio of the phenol derivative to the aliphatic primary alcohol (phenol derivative (mmol) / aliphatic primary alcohol (mmol)) is 0.005 or more and 3 or less.

[0119]

[19] The manufacturing method according to any one of [1] to

[18] , wherein the molar ratio of the phenol derivative to the aliphatic primary alcohol (phenol derivative (mmol) / aliphatic primary alcohol (mmol)) is 0.01 or more and 1 or less.

[0120]

[20] The manufacturing method according to any one of [1] to

[19] , wherein the molar ratio of the phenol derivative to the aliphatic primary alcohol (phenol derivative (mmol) / aliphatic primary alcohol (mmol)) is 0.03 or more and 0.3 or less.

[0121]

[21] The manufacturing method according to any one of [1] to

[20] , wherein the molar ratio of the metal to the aliphatic primary alcohol having 4 or more carbon atoms (metal (mmol) / aliphatic primary alcohol having 4 or more carbon atoms (mmol)) is 0.001 or more and 0.2 or less.

[0122]

[22] The manufacturing method according to any one of [1] to

[21] , wherein the molar ratio of the metal to the aliphatic primary alcohol having 4 or more carbon atoms (metal (mmol) / aliphatic primary alcohol having 4 or more carbon atoms (mmol)) is 0.005 or more and 0.07 or less.

[0123]

[23] The manufacturing method according to any one of [1] to

[22] , wherein the molar ratio of the metal to the aliphatic primary alcohol having 4 or more carbon atoms (metal (mmol) / aliphatic primary alcohol having 4 or more carbon atoms (mmol)) is 0.01 or more and 0.04 or less.

[0124]

[24] The manufacturing method according to any one of [1] to

[23] , wherein the temperature of the oxidation step is 60°C or more and 200°C or less.

[0125]

[25] The manufacturing method according to any one of [1] to

[24] , wherein the temperature of the oxidation step is 70°C or more and 180°C or less.

[0126]

[26] The manufacturing method according to any one of [1] to

[25] , wherein the temperature of the oxidation step is 80°C or more and 170°C or less.

[27] The surface area per unit mass of metal is 60 m 2 / g or more, preferably 60m 2 / g or more 250m 2 / g or less, more preferably 65m 2 / g or more 250m 2 / g or less, more preferably 65m 2 / g or more 200m 2 / g or less, more preferably 70m 2 / g or more 200m 2 / g or less, more preferably 70m 2 / g or more 190m 2 / g or less, more preferably 70m 2 / g or more 180m 2 / g or less, more preferably 70m 2 / g or more 170m 2 / g or less, more preferably 100m 2 / g or more 170m 2 / g or less, more preferably 130m 2 / g or more 160m 2 A manufacturing method according to any one of [1] to

[26] , wherein the amount is less than or equal to / g.

[0127] The present invention will be described in more detail below with reference to examples. In the following examples, the measurement and evaluation of each physical property was performed by the following methods.

[0128] <Method for measuring the surface area per unit mass and particle size of metals> The surface area per unit mass of the metal (ruthenium) was measured using the CO pulse method with a BELCAT-B manufactured by Nippon Bell. Pretreatment for the measurement involved reducing the active metal species (ruthenium) of the sample (catalyst) by passing helium gas through it at 200°C for 15 minutes, followed by passing hydrogen gas through it for 15 minutes. The measurement was performed using a 10% CO / He gas under conditions of 50°C, and the surface area of ​​the active metal species was calculated based on the number of moles of CO adsorbed onto the active metal species before equilibrium was reached. The stoichiometric ratio of the active metal species to CO was set to 1.

[0129] Using the obtained surface area per unit mass of ruthenium, the particle size of the active metal species (ruthenium) was calculated using the following formula based on the ratio of the volume (assuming the sample particles are perfectly spherical) to the surface area per unit mass of ruthenium. The density when ruthenium is used as the active metal species is 12.410 g / cm³. 3 That is the case.

[0130]

number

[0131] In the formula, X is the density (g / cm³) of ruthenium (an active metal species). 3 ) and Y is the surface area per unit mass of ruthenium (m²). 2 It is / g).

[0132] <Method for measuring the mesopore volume of a catalyst> The mesopore volume of the catalyst was measured by mercury intrusion porosimetry in accordance with ASTM standard ASTM D4284-83 (Standard method for measuring the pore volume distribution of catalysts by mercury intrusion porosimetry). Specifically, the mercury intrusion method was performed using Micromeritrics AutoPore IV. The measurement pressure was 1.5 to 60,000 psia, and the equilibrium time was 5 seconds. The mesopore capacity of a catalyst is defined as the cumulative volume of mercury introduced at pressures between 30 MPa and 400 MPa, corresponding to the volume contained in pores with apparent diameters between 2 and 50 nm.

[0133] <Gas chromatography equipment and analytical conditions> GC system: Agilent Technologies, Inc. 7890B, flame ionization detector

[0134] A DB-1 column (capillary column, 100% dimethylpolysiloxane, inner diameter 0.25 mm, length 30 m, film thickness 0.25 μm, manufactured by Agilent Technologies, Inc.) was used. Carrier gas: Nitrogen, 1.5 mL / min Injection conditions: 280°C, split ratio 100 / 1 Injection volume: 1 μL Detection conditions: FID method, 280°C Column temperature conditions: Starting at 100°C, the temperature was held at 100°C for 2 minutes, then increased at a rate of 8°C / min to 180°C, and then increased at a rate of 10°C / min to 280°C. The temperature was then held at 280°C for 5 minutes.

[0135] [Examples, Comparative Examples] In the following examples and comparative examples, "%" refers to "mass%" unless otherwise specified. The following raw materials were used in the reaction. Octanol: Manufactured by Kao Corporation. Toluene: Manufactured by Fujifilm Wako Pure Chemical Corporation, Wako Special Grade. Tetradecane: Manufactured by Fujifilm Wako Pure Chemical Corporation, Wako Special Grade. Diethyl ether: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., Wako Special Grade. BHT: Dibutylhydroxytoluene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., Wako Special Grade), CBP: 2,2'-Methylenebis[6-(1-methylcyclohexyl)-p-cresol] (manufactured by Tokyo Chemical Industry Co., Ltd., Reagent Grade), AO-60: Pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (manufactured by ADEKA Corporation, product name "ADEKA Stab AO-60") AO-80: 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane (manufactured by ADEKA Corporation, product name "ADEKA Stab AO-80") BHA: 3-tert-butyl-4-hydroxyanisole (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., Wako Special Grade)

[0136] [Example 1] In a glass reaction tube with an inner diameter of 34 mm, a 5% alumina-supported ruthenium catalyst (N.E. Chemcat, HYAc-5E, N-type, surface area per unit mass of ruthenium 154 m²) is used as the catalyst. 2 The following were added: ruthenium (particle size 3.1 nm, mesopore volume 0.30 mL / g, dry mass 0.10 g), BHT (dibutylhydroxytoluene) (0.022 g, 0.2 mmol), 1-octanol (0.26 g, 2.0 mmol), toluene (4.0 mL, 3.47 g), and tetradecane (GC internal standard, 0.026 g). An oxygen-filled balloon was connected to the reaction tube to purge the reaction tube with oxygen, and the mixture in the reaction tube was stirred at 90°C for 24 hours. After that, the reaction tube was cooled to 30°C to terminate the reaction.

[0137] The reaction results were obtained by quantitatively analyzing each component using the internal standard method with reaction solutions collected 2 hours and 24 hours after the start of heating and stirring, respectively, using GC (gas chromatography). Using the amounts of each component obtained in the reactant, the initial aldehyde activity (2h) and aldehyde yield (2h, 24h) were calculated according to the following formula. Tetradecane was used as the internal standard, and diethyl ether was used as the solvent. The obtained initial aldehyde activity, aldehyde yield, and the rate of carboxylic acid production as a by-product are shown in Table 1 below.

[0138] Specifically, 0.2 mL of the reaction solution was sampled, and the catalyst was removed by filtering the solution through a membrane filter (polytetrafluoroethylene (PTFE), 0.2 μm). The resulting filtrate was taken into a screw tube containing 2 mL of diethyl ether, diluted, and then subjected to GC analysis.

[0139] <Method for calculating aldehyde initial activity (2h)> The initial aldehyde activity was calculated using the mass of octanal in the reaction solution, obtained by GC analysis of the reaction solution collected 2 hours after the start of heating and stirring, according to the following formula. A higher initial aldehyde activity value indicates better initial activity.

[0140]

number

[0141] <Method for measuring aldehyde yield (2h)> The aldehyde yield (2h) was calculated using the mass of octanal in the reaction solution, obtained by GC analysis of the reaction solution collected 2 hours after the start of heating and stirring, according to the following formula. A higher aldehyde yield value indicates a better yield.

[0142]

number

[0143] <Method for calculating the alcohol conversion rate (24h)> The alcohol conversion rate (24h) was calculated using the mass of octanal in the reaction solution, obtained by GC analysis of the reaction solution collected 24 hours after the start of heating and stirring, according to the following formula.

[0144]

number

[0145] <Method for measuring carboxylic acid production rate (24h)> The carboxylic acid production rate (24 h) was calculated according to the following formula using the mass of octanoic acid in the reaction solution obtained by GC analysis of the reaction solution sampled 24 hours after the start of heating and stirring. The smaller the carboxylic acid production rate value, the better the suppression of carboxylic acid production.

[0146] [Equation]

[0147] [Measurement method of aldehyde yield (24 h)] The aldehyde yield (24 h) was calculated according to the following formula using the mass of octanal in the reaction solution obtained by GC analysis of the reaction solution sampled 24 hours after the start of heating and stirring. The larger the aldehyde yield value, the better the yield.

[0148] [Equation]

[0149] [Measurement method of aldehyde selectivity (24 h)] The aldehyde selectivity (24 h) was calculated according to the following formula using the aldehyde yield and alcohol conversion rate after 24 hours calculated from the reaction solution obtained by GC analysis of the reaction solution sampled 24 hours after the start of heating and stirring.

[0150] [Equation]

[0151] [Examples 2 - 4] It was carried out in the same manner as in Example 1, except that the amount of BHT (dibutylhydroxytoluene) was changed to the amount shown in Table 1.

[0152] [Examples 5 - 9] It was carried out in the same manner as in Example 1, except that the phenolic derivative shown in Table 1 was used instead of BHT (dibutylhydroxytoluene). [Example 10] As a catalyst, a 5% alumina-supported ruthenium catalyst (N.E. Chemcat, HYAc-5E, N-type, surface area per unit mass of ruthenium 154 m²) is used. 2 Instead of using a 5% activated carbon-supported ruthenium catalyst (Johnson Matthey, Type 600, surface area per unit mass of ruthenium 197.3 m²) (ruthenium particle size 3.1 nm, mesopore volume 0.30 mL / g, dry mass 0.10 g), use a 5% activated carbon-supported ruthenium catalyst (Johnson Matthey, Type 600, surface area per unit mass of ruthenium 197.3 m²). 2 The procedure was carried out in the same manner as in Example 2, except that ruthenium (particle size 2.5 nm, mesopore volume 0.24 mL / g, dry mass 0.10 g) was used. [Example 11] As a catalyst, a 5% alumina-supported ruthenium catalyst (N.E. Chemcat, HYAc-5E, N-type, surface area per unit mass of ruthenium 154 m²) is used. 2 Instead of ruthenium particle size 3.1 nm, mesopore volume 0.30 mL / g, dry mass 0.10 g), a 5% activated carbon-supported ruthenium catalyst (manufactured by Kawaken Fine Chemicals, type SD, surface area per unit mass of ruthenium 44.3 m²) is used. 2 The procedure was carried out in the same manner as in Example 2, except that ruthenium particles (particle size 10.9 nm, mesopore volume 0.17 mL / g, dry mass 0.10 g) were used.

[0153] [Example 12] The procedure was carried out in the same manner as in Example 2, except that a 5% alumina-supported palladium catalyst (manufactured by Tokyo Chemical Industry Co., Ltd., dry weight 0.10 g) was used instead of a 5% alumina-supported ruthenium catalyst.

[0154] [Comparative Example 1] The procedure was carried out in the same manner as in Example 10, except that BHT (dibutylhydroxytoluene) was not used.

[0155] Tables 1 and 2 show the initial aldehyde activity, aldehyde yield, and carboxylic acid production rate obtained for Examples 1-12 and Comparative Example 1. Specifically, Tables 1 and 2 show the type of metal-supported catalyst used (catalyst species, support, model number, manufacturer), the amount of metal-supported catalyst, additives, and results. In the term "catalyst," "g" represents the amount of metal-supported catalyst used (g), "Ru[mmol]" represents the amount of metal (Ru) in the metal-supported catalyst used (mmol), and "Pd[mmol]" represents the amount of metal (Pd) in the metal-supported catalyst used (mmol). In the context of "additives," "mmol" refers to the amount (mmol) of phenol derivative used.

[0156] In the "Results," the "Method for Calculating Aldehyde Initial Activity (2h)" was obtained according to the "Method for Calculating Aldehyde Initial Activity (2h)," the "Aldehyde Yield (2h)" was obtained according to the "Method for Measuring Aldehyde Yield (2h)," the "Alcohol Conversion Rate (24h)" was obtained according to the "Method for Calculating Alcohol Conversion Rate (24h)," the "Aldehyde Selectivity (24h)" was obtained according to the "Method for Measuring Aldehyde Selectivity (24h)," the "Carboxylic Acid Production Rate (24h)" was obtained according to the "Method for Measuring Carboxylic Acid Production Rate (24h)," and the "Aldehyde Yield (24h)" was obtained according to the "Method for Measuring Aldehyde Yield (24h)."

[0157] In the table, BHT is dibutylhydroxytoluene. CBP is 2,2'-methylenebis[6-(1-methylcyclohexyl)-p-cresol], AO-60 is pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], AO-80 is 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane BHA is 3-tert-butyl-4-hydroxyanisole DBH is 2,5-di-tert-butylhydroquinone It means...

[0158] [Table 2]

[0159] [Table 3]

[0160] As shown in Tables 1 and 2, it was confirmed that the method of the present invention can produce aliphatic aldehydes in good yield by oxidizing aliphatic primary alcohols having 4 or more carbon atoms.

[0161] On the other hand, in Comparative Example 1, which did not use a phenol derivative, the aliphatic aldehyde yield after 24 hours was significantly lower than the aliphatic aldehyde yield after 2 hours, indicating that carboxylic acids were being produced.

[0162] Furthermore, in the ruthenium-supported alumina catalyst, the aliphatic aldehyde yield after 24 hours was significantly higher than the aliphatic aldehyde yield after 2 hours.

[0163] Furthermore, it was found that the reaction using ruthenium-supported alumina catalyst and BHT as a phenol derivative exhibited high aldehyde selectivity.

Claims

1. A method for producing an aliphatic aldehyde, comprising the step of oxidizing an aliphatic primary alcohol having 4 or more carbon atoms with molecular oxygen in the presence of a phenol derivative and a metal-supported catalyst, The metal-supported catalyst includes a metal supported on an inorganic support, A method for producing an aliphatic aldehyde, wherein the phenol derivative is a compound represented by general formula (I). 【Chemistry 25】 During the ceremony, R 1 This is a hydrocarbon group, hydroxyl group, or alkoxy group which may contain one or more heteroatoms selected from the group consisting of oxygen atoms and nitrogen atoms. R 2 is a hydrogen atom or a linear or branched alkyl group. R 3 and R 4 These are, independently of each other, a hydrogen atom, a linear or branched alkyl group, or a cycloalkyl group which may be substituted with an alkyl group, or R 3 The base is represented by equation (x), and R 4 However, it is a hydrogen atom, a linear or branched alkyl group, or a cycloalkyl group which may be substituted with an alkyl group. However, R 3 and R 4 Except when both are hydrogen atoms. 【Chemistry 26】 [In the formula, R 51 has the same definition as R 1 , R 52 has the same definition as R 2 , and R 54 has the same definition as R 4 . In the formula, * indicates the bonding position.]

2. The manufacturing method according to claim 1, wherein the metal includes ruthenium.

3. The surface area per unit mass of the ruthenium metal is 60 m². 2 The manufacturing method according to claim 1, wherein the amount is 1 / g or more.

4. The manufacturing method according to claim 1, wherein the inorganic support comprises one or more porous oxides selected from the group consisting of alumina, titania, zirconia, silica, silicaalumina, magnesia, zeolite, and activated carbon.

5. The method for producing a product according to claim 1, wherein the aliphatic primary alcohol is an aliphatic linear saturated primary alcohol.

6. The manufacturing method according to claim 1, wherein the molar ratio of the phenol derivative to the metal is 0.7 or more and 10 or less.

7. The manufacturing method according to claim 1, wherein the molar ratio of the phenol derivative to the aliphatic primary alcohol is 0.005 or more and 3 or less.

8. In the formula, R 3 and R 4 The manufacturing method according to claim 1, wherein at least one of the members comprises a branched alkyl group having 3 to 8 carbon atoms.

9. In the formula, R 1 R is an alkyl group having 1 to 5 carbon atoms. 2 R is a hydrogen atom. 3 and R 4 The manufacturing method according to claim 1, wherein each is independently a branched alkyl group having 3 to 8 carbon atoms.

10. The manufacturing method according to claim 1, wherein the temperature of the oxidation step is 60°C or higher and 200°C or lower.

11. The method for producing a primary alcohol according to claim 1, wherein the aliphatic primary alcohol having 4 or more carbon atoms is an aliphatic linear saturated primary alcohol having 8 to 14 carbon atoms.

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