JPS6114140B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an allyl or aryl group-containing first
alcohol, or tri-n of secondary alcohol
- In a method of oxidizing a lower alkyltin alkoxide to obtain a corresponding aldehyde compound or ketone compound, the tri-n-lower alkyltin alkoxide is added with a moderate molar amount or a small excess of a haloamide or haloimide-based oxidizing agent in a nonpolar solvent. The present invention relates to a method for oxidative synthesis of an aldehyde compound or ketone compound, which is characterized in that the corresponding aldehyde compound or ketone compound is obtained by reacting the same.

It has been known that N-bromosuccinimide oxidizes hydroxyl groups to ketones or aldehydes [for example, R. Filler, Chemical Review, Vol. 63, p. 21 (1963)] )reference〕. However, this reaction produces hydrobromic acid in the reaction system, and a salt solvent such as pyridine is often used as a deoxidizing agent, which limits its use.

It has also been reported by K. Saigo, A. Morikawa, T. Mukaiyama, that triethyltin alkoxide can be oxidized with bromine to produce the corresponding ketones and aldehydes.
Chem, Lett, p. 145 (1975). However, this method generates hydrogen bromide, and a large amount of triethyltin methoxide must be added to remove it, and as a result, a large amount of triethyltin bromide is generated, which is unfavorable in terms of purification efficiency. Therefore, it cannot be said to be an industrially advantageous method.

Therefore, a new synthetic method for obtaining ketones or aldehyde compounds more advantageously than alcohols has been desired, particularly in the fine chemical field, for example, in the fields of fragrances, detergents, and medicines.

In view of the above points, the inventors of the present application have conducted extensive research and found that tri-n-
By treating lower alkyltin alkoxide with a haloamide or haloimide-based oxidizing agent such as NBS, it is possible to produce high yield without producing protonic acids such as HBr, and post-processing such as purification process is easy. The present invention was completed by discovering that a ketone or aldehyde compound corresponding to the above can be obtained. That is, in the present invention, products are classified as follows depending on the alcohol used.

(1) In the case of a primary alcohol having an aryl or allyl group, the corresponding aldehyde compound R-CH ₂ OH→R-CHOTBSn→R-CHO (2) In the case of a secondary alcohol, the corresponding ketone compound Examples of primary alcohols having an allyl or aryl group used in the present invention include geraniol, citronellol, allyl alcohol, benzyl alcohol, phenethyl alcohol, and cinnamyl alcohol, and examples of secondary alcohols include: isopropanol, isobutanol,
Examples include 2-pentanol, 2-octanol, cyclohexanol, and cyclododecanol.

The above alcohol is first converted into tri-n-alkyltin alkoxide (first step), which is done by heating the alcohol and bis(tri-n-lower alkyltin) oxide in an aprotic solvent to reflux, and then removing the resulting water. It can be easily obtained by carrying out the reaction while taking it out of the system by azeotropic distillation [Organometallic Compounds 3rd Edition
Vol.1, P444 (1967); Chemistry and
See Industry (London), p. 229-230 (1967)].

As the haloamide oxidizing agent used in the present invention, N
- Bromphthalimide, N-chlorosuccinimide or N-bromsuccinimide, etc., and as the haloamide oxidizing agent, N-bromoacetamide, N-
Examples include chloracetamide, N-iodoacetamide, and N-brombenzamide. Furthermore, as bis(tri-n-lower alkyltin) oxide, bis(tri-n-ethyltin)
Oxide, bis(tri-n-propyltin) oxide, bis(tri-n-pentyltin) oxide, etc. can be used.

In this reaction, since the reaction proceeds approximately quantitatively, each raw material can be used in an equimolar ratio or in a small excess to advantageously advance the reaction.

As the aprotactic solvent used in the first step reaction, any neutral solvent commonly known as an aprotactic solvent such as benzene, carbon tetrachloride, carbon disulfide, dioxane, ether, toluene, etc. or a mixed solvent thereof can be used. Similarly, non-polar solvents that can be used in the second step include benzene,
Any nonpolar solvent or mixed solvent such as carbon tetrachloride, carbon disulfide, cyclohexane, etc. may be used.

In the first step, the reaction of the present invention is preferably carried out at a temperature of 0° or higher in order to maintain the reaction rate at a certain level. If a high boiling point solvent is used, the reaction can be carried out at a temperature of 200°C or higher, but there are few cases where a high temperature of 200°C or higher is required, and the desired reaction can be carried out at a reaction temperature of 200°C or lower. I can do things.

After the first step reaction, the reaction proceeds almost quantitatively, so collect the solvent after cooling and replace the solvent with a non-polar solvent, or if a non-polar solvent is used from the beginning, proceed directly to the second step. However, in some cases, the intermediate product alkoxytributyltin can be used by distilling off the solvent and isolating it under an inert gas atmosphere. It can be used in the next step without any particular purification.

Second step of synthesis of aldehyde and ketone compounds of the present invention
In the step, the alkoxy lower alkyltin obtained in the first step is reacted by adding equimolar moles of a haloamide or haloimide oxidizing agent to recover the solvent, and then distilled to obtain the desired product.

In ester synthesis, a haloamide or haloimide-based oxidizing agent and an aldehyde compound are added to the alkoxy lower alkyltin obtained in the first step in an equimolar amount or in a small excess, and the mixture is reacted in a non-polar solvent, and then cooled to collect the solvent. The target compound can be easily obtained by distilling it under reduced pressure or by isolating it by chromatography.

The reaction conditions for the second step are 0 in any reaction.
A reaction time of 5 minutes to 50 hours at a temperature of 100°C to 100°C is preferable and allows the reaction to proceed.

The present invention will be explained below using examples.

Example 1 20 g (0.2 mol) of cyclohexanol and 37 g (0.1 mol) of bis(tri-n-butyltin) oxide were boiled under reflux while removing water. After distillation of water was completed, toluene was distilled off. The solvent was replaced with carbon tetrachloride, 36 g (0.2 mol) of N-bromsuccinimide was added in portions with stirring so that the reaction temperature did not exceed 35°C, and the reaction was allowed to stir at room temperature for 4 hours. After the reaction is cooled, the precipitated succinimide is filtered, the liquid is concentrated and distilled to obtain cyclohexanone 18.5
g (yield 95%) was obtained. Boiling point 90°~91°C/100mm
Hg.

Example 2 Example 1 was repeated except that 18.4 g (0.1 mol) of cyclododecanol and 34.0 g of bis(tri-ethyltin) oxide were used to obtain cyclododecaoxytriethyltin, in addition to 22.6 g of N-bromphthalimide ( 0.1 mol) was added and reacted in the same manner as in Example 1, and further treated in the same manner to obtain 16.7 g (yield: 90%) of cyclododecanone.

The obtained cyclododecanone was identified by comparing it with the physical constants of confirmed samples.

Example 3 Example 1 was repeated, except that 26.0 g (0.2 mol) of 2-octanol was used and treated in the same manner.
21.0 g (yield 82%) of methylhexyl ketone was obtained.

n ²⁰ _D 1.415, bp 172-173°C, d ²⁰ ₄ 0.824 Example 4 22.0 g (0.2 mol) of benzyl alcohol in toluene and 48.0 g (0.1 mol) of bis(tri-n-propyltin) oxide in water in carbon tetrachloride. The mixture was boiled under reflux until no more water was distilled out, and after cooling, 19.8 g (0.2 mol) of N-chloroacetamide was added to the reaction mixture, and the reaction was allowed to proceed at a temperature of 60°C for 3 hours. After the reaction was completed, the solvent was distilled off, and the mixture was vacuumed. Distillation yielded 18.2 g of benzaldehyde (yield: 86%).

n ²⁰ _D 1.545 Example 5 31.0 g (0.2 mol) of geraniol (3,7-dimethyl-2,6-octadien-1-ol) was dissolved in 61.0 g (0.1 mol) of bis(tri-n) in benzene.
-Butyltin) oxide and the solvent are reacted while distilling off water under reflux boiling, and after no more water is distilled off, the reaction system is cooled and N-brombenzamide 61 is added to the reaction system.
g (0.2 mol), reacted at 10°C for 5 hours, cooled and precipitated benzimide,
Concentrate the liquid to obtain geranial (3,7-dimethyl-
18.8 g (yield: 60.5%) of 2,6-octadiene-1-al) was obtained.

Geranial was fixed as a hydrazone by comparing it with the physical constant of a confirmed sample.

Claims (1)

[Claims] 1. A method for obtaining a corresponding aldehyde compound by oxidizing a tri-n-lower alkyltin alkoxide of a primary alcohol having an allyl or aryl group, wherein the tri-n-lower alkyltin alkoxide is 1. A method for oxidative synthesis of aldehyde compounds, which comprises adding a moderate molar amount or a small excess of a haloamide or a haloimide-based oxidizing agent to a nonpolar solvent and reacting to obtain a corresponding aldehyde compound. 2. In a method of oxidizing a tri-n-lower alkyltin alkoxide of a secondary alcohol to obtain a corresponding ketone compound, the tri-n-lower alkyltin alkoxide is oxidized in a nonpolar solvent in a moderate molar amount or a small excess of haloamide or A method for oxidatively synthesizing a ketone compound, which comprises adding a haloimide oxidizing agent and causing a reaction to obtain a corresponding ketone compound.