JPS5838226A - Preparation of unsaturated carbonyl compound - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a raw material for the preparation of perfumery, pharmaceuticals, etc., in high catalytic activity, in high yield, without side reactions, by the dehydrogenative oxidation of an unsaturated alcohol using ruthenium (II) dioxide as a catalyst, in the presence of an oxygen supplying material. CONSTITUTION:An unsaturated alcohol of formulaI(R<1>, R<2>, R<3> and R<4> are H, alkyl, alkenyl, or aryl) is subjected to the dehydrogenative oxidation at 50- 120 deg.C in the presence of a ruthenium (IV) dioxide catalyst in an oxygen-supplying material such as oxygen gas, air, etc. to afford the unsaturated carbonyl compound of formula II. The reaction is preferably carried out by adding an antioxidant to the system and diluting the system with a solvent to suppress the side reactions. The antioxidant is, e.g. 2,6-di-t-butyl-p-cresol, etc. and its amount is <=1pt.wt. per 100pts.wt. of the reaction materials. The ruthenium dioxide is preferably used in the form having a surface area of as large as possible.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of an unsaturated carbonyl compound represented by the general formula (wherein R1, R2, R'Fi is hydrogen, an alkyl group, an alkenyl group or an aryl group). It is about law. More specifically, the present invention is directed to the production of a compound of the general formula (wherein R1, R2, R3, and R4 are hydrogen, an alkyl group, an alkenyl group, or an aryl group) in the presence of a ruthenium dioxide (transfer) catalyst in an oxygen supplying substance. The present invention relates to a method for producing an unsaturated carbonyl compound represented by the general formula (I) by dehydrogenating and oxidizing an unsaturated alcohol represented by the formula (I). The unsaturated carbonyl compound represented by the above general formula (0) is widely used as fragrances, pharmaceuticals, etc., or raw materials for their production.

Conventionally, in order to produce the unsaturated carbonyl compound represented by the general formula (I) from the unsaturated alcohol represented by the general formula (1), the unsaturated carbonyl compound represented by the general formula (I) is oxidized using a reagent oxidizing agent such as manganese dioxide. Methods [New Experimental Chemistry Course 15
(See Maruzen (1976)), (b) Oxygen oxidation method using a platinum catalyst [New Experimental Chemistry Course 15 Maruzen (1976)
)], (c) Oxygen oxidation method using a complex catalyst such as tristriphenylphosphine ruthenium dichloride (Ise, Matsumoto, Proceedings of the 43rd Spring Annual Meeting of the Chemical Society of Japan, IL36.1981), etc. are known. It is being However, method 0) requires the use of oxidizing reagents in a stoichiometric manner, and is not suitable for industrial use due to the problem of processing power of the resulting reduction product. The method (b) has problems in selectivity, such as the production of carboxylic acids and the like as by-products.

Since the method e→ has low catalytic activity, is complicated to prepare the catalyst, and uses a phosphine complex that is unstable under oxidation conditions as a catalyst, it is difficult to reuse the catalyst.

As a result of studies to overcome the drawbacks of conventional methods, the present inventors discovered an industrial method for easily converting unsaturated alcohols into corresponding unsaturated carbonyl compounds with good yield, and completed the present invention.

Examples of the unsaturated alcohol represented by the general formula (2), which is a raw material of the present invention, include allyl alcohol, crotyl alcohol, frenol, keraniol, nerol, farnesol, retinol, 2-(β-yonyritene)/U,
Unsaturated primary alcohols such as cinnamyl alcohol and 3
Examples include unsaturated secondary alcohols such as -hydroxytobutene, 3-hydroxy-1-phenyl-1-butene, β-ionol, and carveol.

The method of the present invention requires that the unsaturated alcohol represented by the general formula (2) be reacted in the presence of a ruthenium dioxide catalyst in an oxygen supplying substance. The term "oxygen supply substance" as used herein means oxygen gas, a mixed gas of oxygen and an inert gas, air, or the like.

The ruthenium dioxide used in the present invention is commercially available anhydrous ruthenium dioxide (converted), hydrated ruthenium dioxide (V), or ruthenium dioxide (converted) prepared from ruthenium compounds such as ruthenium halides and ruthenium tetroxide.
Any of these may be used, but it is preferable to use a form with as large a surface area as possible. In addition, for use in the reaction, it may be used in a homogeneous system or supported on a carrier such as silica gel, aluminum lotus, activated carbon, etc. using the above-mentioned ruthenium dioxide (trans)t-powder or any technique commonly used for the production of heterogeneous catalysts. It may be used as a heterogeneous system in which the mixture is dispersed in a reaction solution.

Although it is not necessary to use a solvent in carrying out the present invention, if it is desired to use a solvent, for example, a saturated hydrocarbon such as pentane, hexane, heptane, or a mixture thereof, dichloromethane, chloroform, tetrachloride, etc. Carbon, dichloroethane, trichloroethane, 1.1, 2.2
- Tetrachloroethane - Halosaponified hydrocarbons, aromatic hydrogens such as benzene and toluene, carbonyl compounds such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran, dioxane, l,2-dimethoxyethane, and saturated alcohols such as methanol and ethanol. I can give an example of gin.

'19 When carrying out the present invention, it is preferable to add an antioxidant to the reaction system in order to suppress side reactions and to dilute the anti-oxidant with a bath medium. When using antioxidants,
2.6-di-t-butyl-p-cresol, 2,4. −
6-) So-called hindered phenols such as di-t-butylphenol and 2,6-di-t-butylhydroquinone can be used. In addition, the amount of antioxidant used is
An it ratio of 1/100 or less relative to the reaction substrate is sufficient.

In the present invention, the oxidation reaction proceeds at atmospheric pressure and at room temperature, but from the viewpoint of reaction efficiency, the reaction temperature is preferably in the range of 50 to 120C, and oxygen supply such as pressurized oxygen or air. Preferably, the reaction is carried out under a clean atmosphere.

The feature of the present invention is that the unsaturated alcohol of the general formula (2) can be easily converted into the unsaturated carbonyl compound of the general formula (2) in the presence of an oxygen-supplying substance by using a Ruthenium Dioxide Co., Ltd. catalyst. In addition, the stereochemistry of raw materials and products is largely maintained during the reaction process, and unsaturated bonds and active functional groups are not oxidized in many oxidation reactions.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 2.0 g of geraniol and hydrated ruthenium dioxide (Incorporated)
Ru02-XH201 moisture content 27.5%, Ru55%)
(Man/fa Products) 5011f 1
The mixture was heated and stirred for 12 hours at 55 to 60 rpm in an oxygen atmosphere at atmospheric pressure.

The reaction mixture was applied to a silica gel column and flushed with dichloromethane to obtain citral C130wq'5r and geraniol 3701q.

Example 2 Hydrous ruthenium dioxide (transfer) 5011F powder similar to that used in Example 1 was suspended in a solution of 2.0 g of geraniol dissolved in 8 d of dichloromethane, and the mixture was heated at 90° C. under an oxygen atmosphere (7 days limit). The mixture was heated and stirred at ~95C for 3 hours. The reaction mixture was analyzed by GLC (XP60 20L 2m.

When analyzed with 160・), 50.5-geraniol was 7 toral (trans:cis=93:7)+
(I found out that it was Qt transformed.

Example 3 10 parts of geraniol, 1 part of ruthenium dioxide similar to that used in Example 1, 0.1 part of 2,6-di-t-butyl-p-cresol; 5 parts of chef; t) Reflux temperature of toluene While stirring, oxygen gas was blown into the solution for 1.2 hours. The reaction mixture was analyzed by GLe, NMR, TLC.
When analyzed, it was found that 71 citral was produced. The remainder was essentially geraniol containing a small amount of nerol tubules.

Example 4 Hydrous ruthenium dioxide 50q similar to that used in Example 1
A well-prepared solution of ruthenium tetroxide in methylene chloride (approximately 5 MJ) was added to 15 g of geraniol with stirring.

Dilute this with 80 sl of methylene chloride and
The mixture was heated and stirred at 85 to 90 C for 6 hours in the presence of 5 oiv of -butyl-p-cresol in an oxygen atmosphere (4-5 atm). When the reaction mixture was analyzed in the same manner as in Example 3, it was found that 14 hours of geraniol had been converted to citral.

Example 5 145q of ruthenium dioxide, 1 prepared methylene chloride solution of ruthenium tetroxide (approximately 15 m/t), and 50 g of geraniol were added. Add to this 2,6-sheet t-petit rou p-
500 qt of cresol was added, and the mixture was heated and stirred at a reaction temperature of 60 to 75 C under an oxygen atmosphere of 8.5 atm for 11.5 hours. When the reaction mixture was analyzed in the same manner as in Example 3, 3
It was found that 6% of geraniol was converted to citral.

Example 6 Hydrous ruthenium dioxide 501 similar to that used in Example 1
IF and carveol 1. The mixture was dissolved in Ogt-methylene chloride 2d and reacted for 48 hours at 65-70C in an atmosphere of oxygen (1 atm). When the reaction mixture was separated and purified using silica gel column chromatography, carvone was obtained in a yield of 34%, and unreacted carveol was quantitatively recovered.

Example 7 Prenol 10. 50 μm of hydrated ruthenium dioxide and 2,6-di-t-butyl-p as used in Example 1 for Og.
- Add 50q of cresol and add 1 atm under oxygen atmosphere of 7 atm.
The mixture was heated and stirred at 00C for 14 hours.

A portion of the reaction mixture was diluted with approximately 50 times more carbon tetrachloride, filtered to remove the catalyst, and the solution was purified with NM spectromethyl 2-
It was revealed that it was converted to butinal. Note that, other than the aldehyde mentioned above, there was virtually no change in prenol.

Patent Applicant Procedures Amendment @ (Voluntary) July 12, 1980 Haruki Shimada, Commissioner of the Japan Patent Office 1. Indication of the case ← 1982 Can Patent Application No. 13549J 2o Name of the invention Process for producing unsaturated carbonyl compounds 3゜Column 5 of ``Detailed Description of the Invention of Part 1 of the Person Making the Amendment'', Contents of the Amendment d) Corrected ``Topden'' in line 2 of page 5 of the specification to ``1-butene'', and changed lines 15 to 16. ``Good but as much as possible,''
” should be corrected to “Good, but as much as possible.”

■ "Alcohols, etc." on page 6, lines 15-16 will be corrected to "carbo/WI esters, etc. of alcohol-2-ethyl sulfate, propyl acetate, butyl acetate, adenyl acetate, etc."

6) [Added on page 10, line 6]. ” was added (substantially KFi) Ruthenium dioxide is generated in this state.

). ” is corrected.

that's all

Claims (1)

[Scope of Claims] An unsaturated carbonyl compound represented by the general formula, characterized in that an unsaturated alcohol represented by the general formula is dehydrogenated and oxidized in the presence of a ruthenium dioxide (transfer) catalyst in an oxygen supplying substance. Manufacturing method (in the formula
R1, R2, R3 and R4 are hydrogen, an alkyl group, an alkenyl group or an aryl group. ).