JPS6032612B2 - Alcohol manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for hydrogenating Q,8-unsaturated aldehydes.

More specifically, the present invention relates to a method for hydrogenating Q,8-monounsaturated aldehydes to produce alcohols in which the aldehyde group and the unsaturated bond at the Q,8 position are selectively hydrogenated. Hydrogenation of Q,6-unsaturated aldehydes, especially Q,8-unsaturated aldehydes having at least one further double bond in addition to the double bond in the Q,8 position, according to known methods results in It was not possible to selectively produce alcohols in which only the double bond at the 8-position and the aldehyde group were hydrogenated at the same time, and only the double bond at the Q and B positions or only the aldehyde group were hydrogenated. Either a compound was obtained, or a compound in which all double bonds including the Q and 8-position double bonds and aldehyde groups were hydrogenated was obtained.

For example, Hakama Seki No. 49-12661 describes a method of hydrogenating citral in the presence of a platinum-cobalt catalyst, as represented by the following formula. According to this method, only the aldehyde group is hydroxylated. A compound converted to a methyl group was obtained, and a small amount of a compound in which a double bond and an aldehyde group were hydrogenated at the Q and 8 positions was obtained.

On the other hand, Samurai Publication No. 49-154322 describes a method of hydrogenating citral in the presence of a palladium-alkali metal or alkali metal catalyst, as represented by the following formula, and according to this method, Q, The double bond at the B-position is hydrogenated, but the aldehyde group remains (as is) and is not hydrogenated.

Therefore, the present inventors conducted research on a method for producing a corresponding alcohol by selectively hydrogenating the aldehyde group and the double bond at the Q and B positions of a Q,8-unsaturated aldehyde. We have already proposed a catalyst that has excellent activity.

As a result of further research into the proposed method, the present inventors discovered that the desired alcohols could be obtained with even higher selectivity by using a catalyst containing platinum, nickel, and iron. reached. That is, the present invention relates to the following general formula (1) [wherein R,, R2 are the same or different and represent a hydrogen atom or an alkyl group, and R3 is a carbon number having an unsaturated aliphatic group or an unsaturated alicyclic group. Indicates a hydrocarbon group of 40 or less.

] Q,8 monounsaturated aldehydes represented by platinum,
The following general formula (0) [wherein R,
, R2 and R3 are the same as above].

In particular, according to the present invention, when an aldehyde having a double bond in addition to the double bond at the Q, 31 position is hydrogenated, alcohols with selectively saturated double bonds at the Q, B-position become highly It can be obtained with high conversion rate and high selectivity. Alcohols synthesized by the method of the present invention, such as citronellol obtained by hydrogenating citral, are important as perfumes, and various terbenes are important as perfumes or as intermediates in the synthesis of various terbenes.

Q,8 used as starting material in the method of the invention
-The unsaturated aldehyde is represented by the following general formula (1) [wherein R,,R
2 represents the same or different hydrogen atom or alkyl group, R
3 represents a hydrocarbon group having 40 or less carbon atoms and having an unsaturated aliphatic group or an unsaturated alicyclic group.

]. In general formula (1), R and R2 represent a hydrogen atom or an aldehyde group, and the aldehyde group may be linear or branched.

Further, the number of carbon atoms in the aldehyde group is not particularly limited, but it is generally 20 or less, particularly preferably 5 or less.

When R and R2 are aldehyde groups, examples thereof include methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-phthyl, isobutyl, amyl, isoamyl, and t-amyl. R3 in (1) is a hydrocarbon group having 40 or less carbon atoms and having an unsaturated aliphatic group or an unsaturated alicyclic group.

The hydrocarbon group may contain a group inert to the reaction, such as a halogen, a carbonyl bond (ketone), an ether bond, an ester bond, a carboxyl group, a hydroxyl group, etc. Preferred specific examples of such Q,8 monounsaturated aldehydes are explained below, but the present invention is not limited thereto in any way.

Q' Aliphatic aldehydes: For example, 2,6 nonadienal, 6-methylcitral, cytolidene acetaldehyde, cytotolidene propionaldehyde, furnesal, geranylgeranial.

[21 Alicyclic aldehydes; For example, cyclocytolylideneacetaldehyde, cyclocytolylidenepropionaldehyde, methylional, ionylideneacetaldehyde, dihydroretinal, tetrahydroretinal.

'3} Aromatic aldehyde; For example, penzylidene citronellal.

{41 heteroaldehyde; e.g. 2-methyl-3-furfuryl-acrolein,
2-ethyl-3-furfuryl acrolein, 2-propyl-furfuryl acrolein, 3-methyl-4-furfuryldene-butyraldehyde.

The reaction in the present invention is generally preferably carried out in the liquid phase.

In this case, a solvent may or may not be used, but it is advantageous to use a solvent. When using a solvent, any solvent may be used as long as it does not adversely affect the reaction, and for example, the following solvents can be used. (1) Aliphatic hydrocarbons; for example, propane, butane, bentane, hexane, heptane, octane, etc. (0
) Alicyclic hydrocarbons; for example, cyclohexane, methylcyclohexane, ethylcyclohexane, decalin, etc.; (m) aromatic hydrocarbons; For example, benzene, triene, xylene (ol/, meta, para), cumene, tetralin, etc., (N) halogenated hydrocarbons; for example, carbon tetrachloride, methylene chloride, chloro.

Form, dichloroethane, trichloroethane, tetrachloroethane, chlorobenzene, dichlorobenzene, perchloroethylene, etc., (V) ether; for example, diethyl ether, tetrahydrofuran, dioxane, etc., (W
) Esters; For example, ethyl acetate, butyl acetate, methyl benzoate,
Dimethyl phthalate, diethyl phthalate, dibutyl phthalate, etc., (W) ketone; For example, acetone, methyl ethyl ketone, dibutyl ketone, cyclohexanone, etc. (Skin) Alcohol: For example, methanol, ethanol, n-propanol, isopropanol, n-butanol, Isobutanol, t-butanol, n-aluminum alcohol, isoamyl alcohol, cyclohexanol, phenyl ether alcohol, etc.

Among these solvents, particularly preferred are (1) aliphatic hydrocarbons, (0) alicyclic hydrocarbons, (m) aromatic hydrocarbons, (air) alcohols, and (river) esters, especially those containing carbon. The number is less than 20.

When the above-mentioned solvent is used, it is used in an amount of 0.01 to 20 parts by weight, preferably 0.1 to 100 parts by weight, per 1 part by weight of Q,8 monounsaturated aldehyde as the starting material. According to research by the present inventors, when alcohol is used as a solvent, in the reaction system of the present invention, for the unsaturated aldehyde,
It has been found that the selectivity of the corresponding alcohol can be improved by the presence of water in an amount not exceeding 20 moles, especially 0.5 to 5 moles.

If the amount of water exceeds 20 moles, the conversion rate of unsaturated aldehyde will improve, but the selectivity of the corresponding alcohol will decrease, which is not preferable. The catalytic reduction reaction with hydrogen in the present invention can be carried out from the Q,8 monounsaturated aldehyde of the general formula (1) with a high conversion rate and high selectivity by using a collective catalyst containing platinum, nickel, and iron. You can search for alcoholic beverages corresponding to (b).

In the method of the present invention, when only platinum is used as a catalyst, alcoholization of aldehydes and hydrogenation of unsaturated bonds other than Q,8 unsaturated bonds occur, resulting in a decrease in the target selectivity, and the objective of the present invention cannot be achieved. .

On the other hand, when a solid catalyst containing platinum and nickel is used as a catalyst, Q of general formula (1) can be obtained with a considerably high selectivity.
, 8-unsaturated aldehyde can be used to extract the reacting alcohol of general formula (D).

However, when a solid catalyst containing platinum, nickel and iron is used in the method of the present invention, the target product is produced with surprisingly high selectivity. Therefore, in the present invention, it is believed that the purpose can be achieved with surprisingly high selectivity only by combining platinum with nickel and iron.

The catalyst used in the present invention preferably contains a nickel compound and an iron compound on the surface of platinum, and its preparation method includes, for example, '11: Mixing salts of the above two types of metals into the reaction raw material solution. Then, separately add a platinum catalyst.
'2} One of the above two types of salts is mixed into the reaction raw material liquid, and the other salt and a platinum catalyst are separately added.

(2) Treat the platinum oxide catalyst in advance with salts of the above two metals in a hydrogen atmosphere or the like. {4} Add by an appropriate method when preparing a platinum catalyst.

'5- Mix one of the above two types of metal salts into the reaction raw material solution, and separately add a platinum catalyst prepared with the other one according to the method of [3] or {4} above. Examples of methods include: In the present invention, for example, when the solid catalyst is continuously and repeatedly used in a continuous reaction, at least the surface of platinum is maintained so that nickel and iron always satisfy the conditions described later, thereby increasing the target alcohol. It can be used with high conversion rate and high selectivity.

The nickel compound and iron compound used are preferably those that are at least partially soluble in the reaction system, and may be either inorganic acid salts or organic acid salts.

These include, for example, sulfates, nitrates, phosphates, halides (eg chlorides), carbonates, acetates, formates, oxalates and the like, with sulfates and acetates being particularly preferred. On the other hand, as a method for preparing platinum oxide, for example, or bait nicSynthesesCol. , soil, 463
(1948), a method of preparing hexachloroplatinic acid by treating it with sodium nitrate, a method of treating ammonium hexachloroplatinate with sodium nitrate, and the like.

The catalyst used in the present invention may be used by itself, or may be a platinum-based catalyst supported on a suitable carrier such as Katsura Minato, pumice, silica gel, alumina, silica alumina, activated carbon, etc. used.

In the present invention, platinum is added in an amount of 1 x 10-6 to 0.5 gram atom, preferably 1 x 10-5 to 0.1 gram atom per mole of Q,8 monounsaturated aldehyde as the starting material. It is advantageous to use the range.

The amount of nickel used in the present invention is the amount of platinum used.
For gram atoms, a range of 1×10 −3 to 50 gram atoms, preferably 5×10 −3 to 20 gram atoms, particularly preferably 1×10 −2 to 10 gram atoms is used.

The amount of iron used in the present invention is 0.5 x 10-3 to 50 gram atoms, preferably 1 x 10-3 to 20 gram atoms, particularly preferably 2
A range of x10-3 to 10 gram atoms is used. The valence of nickel in the nickel compound is usually 0 or 2,
Tetravalent, particularly divalent, is preferred. On the other hand, the valence of iron in the iron compound is usually 0, 2 or 3, and preferably 2 or 3.
In the present invention, the ratio of the amounts of nickel and iron used is
The amount used for platinum is within the above range, and the ratio of nickel and iron is within a certain range, that is, the following formula (m) is 0.4
8 paper 0.82<A<0.48 0.33...(m
) Preferably, the following formula (W)0.48-0.57<A<
0.48 0.16 ... (N) In the formula, A is Fe/Pt
(y-atom/t-atom), B is Ni/Pt (t-atom/t-atom),
ter atom).

It is particularly advantageous to satisfy the range . The platinum-based catalyst is generally insoluble in the reaction system, and may be used in any of a fixed bed type, fluidized bed type, moving bed type, suspended bed type, etc.

The hydrogenation reaction in the present invention is advantageously carried out at 0 to 300°C, preferably 10 to 200°C, particularly preferably 20 to 100°C.

If the reaction temperature is lower than 0°C, the conversion rate of unsaturated aldehyde will decrease, while if it exceeds 300°C, side reactions such as hydrogenolysis will actively occur and the selectivity of the target alcohol will decrease. In addition, the hydrogen partial pressure in the present invention is 0.5 to 300k.
9/m, preferably in the range of 0.8 to 200k9/m.

When the hydrogen partial pressure is lower than this range, the conversion rate of unsaturated aldehyde decreases, or when the hydrogen partial pressure is higher than the above range, the alcohol selectivity decreases. Further, the hydrogen may be not only pure hydrogen but also a mixed gas of an inert gas and hydrogen. The present invention can be carried out either batchwise or continuously, and the method of contacting hydrogen gas may be either countercurrent or cocurrent.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

Example 1 0.5 parts of platinum oxide, 0.625 parts of nickel acetate, 0.25 parts of ferrous sulfate,
and 125 parts of 90% methanol (10% is 20%) and allowed to simmer at room temperature for 30 minutes under a hydrogen partial pressure of 10k9/c.

After that, the upper lighting solution was removed, and 38.5 parts of citral and 125 parts of 90% methanol were added to make the hydrogen partial pressure 10k9/
The reaction was carried out under Iso G at a reaction temperature of 90°C for 1 hour and 30 minutes. After removing the catalyst from the reaction mixture, the product was analyzed by gas chromatography. As a result, citral was almost completely converted, and citronellol was 95.8 mol%.
was obtained in a yield of .

Examples 2-3 The reaction was carried out in the same manner as in Example 1 except that the amounts of nickel acetate and ferrous sulfate were changed and the reaction time was different, and the following results were obtained.

Comparative Examples 1 and 2 A reaction was carried out in the same manner as in Example 1 except that the amounts of nickel acetate and ferrous sulfate were changed and the reaction time was different, and the following results were obtained.

Claims (1)

[Claims] 1 The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R_1 and R_2 are the same or different and represent a hydrogen atom or an alkyl group, and R_3 is an unsaturated aliphatic group or Indicates a hydrocarbon group having 40 or less carbon atoms and having an unsaturated alicyclic group. ], α,β-unsaturated aldehydes represented by platinum,
The following general formula (II), which is characterized by catalytic reduction with hydrogen in the presence of a catalyst containing nickel and iron, has numerical formulas, chemical formulas, tables, etc. [In the formula, R_1, R_2, and R_3 are defined as above. Same as〕
A manufacturing method for alcohols represented by