JPS5824414B2 - Keton no Shinkinaseizouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for producing ketones represented by the following general formula.

(In the above formula, R1 represents an alkyl group or a cycloalkyl group, and R2 represents a hydrogen atom, an alkyl group, or a cycloalkyl group.

R3, R4, and R5 represent a hydrogen atom, a methyl group, or an ethyl group.

R9 is an alkyl group having 1 to 4 carbon atoms, or as a method for synthesizing the compound represented by the above formula,
No. 28324 and Japanese Patent Publication No. 46-7933 propose a method of directly adding 2,6-dialkylphenol and a vinyl ketone compound in an organic solvent in the presence of a basic catalyst. - A method in which 4-hydroxybenzaldehyde and ketones are condensed in alcohol using gaseous hydrogen chloride as a catalyst, and then hydrogenated (German Published Publication No. 2009504, OrganicRea
ctions, Volume 16, Bull, Soc.
Chim.

F' Lance, Vol. 1954, pp. 522-3) has been proposed.

However, these methods have drawbacks as described below, and cannot be said to be practically advantageous methods.

In other words, when using vinyl ketone compounds, special catalysts and/or special solvents must be used.Furthermore, vinyl ketone compounds are very unstable substances and easily polymerize, making it difficult to recover the product. The rate is also low.

In the method of condensing benzaldehyde and ketone, the reaction operation is complicated and the reaction must be carried out in two steps, resulting in a low yield.

The inventors of the present invention made extensive studies to solve these drawbacks, and as a result, they discovered a method for easily producing ketones represented by the above general formula with good yield, and completed the present invention.

That is, the present invention is based on the general formula (wherein R1 represents an alkyl group or a cycloalkyl group,
R2 represents a hydrogen atom, an alkyl group, or a cycloalkyl group) and a compound represented by the general formula (where R3, R4, R
5 each represents a hydrogen atom, a methyl group or an ethyl group.

R6 each has 1 or more carbon atoms and represents an alkyl group, cycloalkyl group, allyl group, or aralkyl group, and R7 and R8 may jointly form a 5- to 7-membered ring with the bonded nitrogen atom). A method for producing ketones represented by the general formula (wherein R1, R2, R3, R4, R5 have the same meanings as described above, and R9 is alkyl having 1 to 4 carbon atoms) Regarding.

The compounds obtained by the method of the present invention are plastics,
It is useful as an antioxidant for organic materials such as fats and oils or as an intermediate raw material thereof.

Examples of compounds represented by the general formula that are raw materials of the present invention include 2,6-di-tert-butylphenol, 2-methyl-6-tert-butylphenol, and 6-(1,1,3,3-tetramethylbutylphenol). )−0
-cresol, 2-tert-butylphenol, 2-(1.
Examples include 1,3,3-tetramethylbutylphenol, 2-ingrovirphenol, 0-cresol, and 2-tert-butyl-5-methylphenol.

The compound represented by the general formula, which is another raw material of the present invention, can be synthesized by condensing the compound with a secondary ammonium salt in a suitable solvent in the presence of a suitable catalyst, such as acetone, methyl ethyl ketone, methyl ethyl ketone, etc. , diethyl ketone, ethylpropyl ketone, diisopropyl ketone, etc.

Examples of the aldehyde represented by are formaldehyde, acetaldehyde, and examples of the probilaldehyde include diethylamine, dipropylamine, diphenylamine,
Examples include dibenzylamine, morpholine, piperidine, and the like.

HX represents hydrogen halide such as hydrogen chloride.

In the present invention, the above-mentioned two types of starting compounds can be reacted in the presence or absence of a basic catalyst, and in the presence or absence of a suitable solvent; Examples of the basic catalyst include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal alkoxides, alkali metal amides, alkaline earth metal hydroxides or alkoxides, and quaternary ammonium salts.

Examples of solvents that can be used in the present invention include dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dioxane, tetrahydrofuran, acetone, cyclohexanone, methanol, ethanol, propatool, impropatol, butanol, tertiary butanol, Examples include polar solvents such as hexamethylene phosphoroamine.

To carry out the desired reaction according to the invention, the temperature range is from 20'C to 200°C, preferably from 60'C to 160°C.
A temperature range of °C is used.

The manufacturing method according to the present invention has the following advantages.

1. There is no need to use a special catalyst (it can be produced using inexpensively available sodium hydroxide, potassium hydroxide, sodium methoxide, etc., and can even be produced without a catalyst).

2. There is no need to use a special solvent, and ordinary polar solvents can be used, and furthermore, production without a solvent is also possible.

3. All the compounds used as raw materials can be commercially available and can be obtained in large quantities at low cost. Furthermore, the raw materials are stable, so the yield will not decrease due to side reactions such as polymerization of the raw material compounds. Unreacted raw materials can be easily recovered and reused.

The present invention will be explained in more detail with reference to the following examples, but the present invention is not limited by these examples.

Example 1 Preparation of 2-(3',5'-ditert-butyl-4'-hydroxyphenyl)ethylmethylketone 70.4F diethylamine hydrochloride, 27.6F paraformaldehyde, 240rrtl acetone, 30m
1 of methanol and 100 mJ of water are reacted under reflux for 10 hours, and after cooling, the amine is separated by treatment with sodium hydroxide solution.

Extracted with ether and distilled to 60-b Ethylamino-3-butanone was obtained.

20.6f 2,6-di-tert-butylphenol, ■, 7
14.6P of 1-diethylamine-3-butanone was added dropwise to 60°C of potassium hydroxide and 60ru of dimethyl sulfoxide with stirring at 60°C, and the mixture was allowed to react at this temperature for 18 hours.

After distilling off the solvent, benzene is added and the mixture is washed with dilute hydrochloric acid.

157-159°C/0.45 mynH by distillation
23.5 S' of pale yellow liquid was obtained.

Similarly, instead of 2,6-di-tert-butylphenol, 2-methyl-6-tert-butylphenol, 6-(1'
- Reaction with 1', 3', 3'-tetramethylbutyl)-0-cresol gave the corresponding substituted ethyl methyl ketone.

Example 2 Production of i-(2'-methyl-5'-tert-butyl-4'-hydroxyphenyl)-2-methylpentanone-3 The same procedure as in Example 1 was carried out using diphenylamine hydrochloride, diethyl ketone, and paraformaldehyde. 1-diphenylamino-2-methylpentanone-3 was synthesized.

16.4P of 2-tert-butyl-5-methyl-phenol, 1.22 of powdered sodium hydroxide, and 50rrtl of dimethylformamide were heated to 60°C and 1 of 2S, O;
-Diphenylamine-2-#-lupentanone-3 is added dropwise.

After the dropwise addition, the temperature was raised to 80°C and the mixture was reacted for 16 hours.

The solvent is distilled off under reduced pressure and benzene is added.

Distilled after washing with dilute hydrochloric acid and heated to 152-155°C, 70.5 mm.
22.5f of pale yellow liquid was obtained with Hg.

Similarly, the corresponding ketone was obtained by using 2-isopropyl-5-methylphenol instead of 2-tert-butyl-5-methylphenol.

Moreover, when the same procedure as in Example 2 was carried out except for using 1.21 sodium hydroxide, the target compound 12.6P was obtained.

Example 3 Production of 1-(3'-37'thyl-4'-hydroxyphenyl)-2-ethylbutanone-3 Diethylamine hydrochloride, methylpropyl ketone, baraforma/1/7' H)” Yori 1
-Diethylaminol 2-nitylbutanone-3 was synthesized.

2-Tertiary butylphenol 15.0'? , 1.61 g of sodium methoxide was heated to 80°C, and 317.1 g of -diethylamine-2-ethylbutanone was added dropwise.

After completion of the dropwise addition, the temperature was raised to 120°C and stirred for 24 hours.

After cooling, add benzene, wash with diluted hydrochloric acid, and distill.145-b 18.12 of a yellow liquid was obtained.

Similarly, instead of 2-tert-butylphenol, K, 2-
The corresponding ketones were obtained using isopropylphenol and 0-cyclohexylphenol.

Example 4 Production of l-(3',5'-di-tert-butyl-4-hydroxyphenyl)-1-methylbutanone-3 In the same manner as in Example 1, 1- was prepared from morpholine hydrochloride, acetaldehyde and acetone. Morpholino-1-methylbutanone-3
was synthesized.

20.6P 2,6-di-tert-butylphenol, 1.2
1 of sodium hydroxide is dispersed in 60 ml of tertiary butanol and heated and stirred at 80°C.

17. IP of 1-morpholino-1-methylbutanone-
3 was added dropwise and allowed to react at this temperature for 24 hours.

After the reaction, the solvent is distilled off under reduced pressure, benzene 1001711 is added, and the mixture is washed with dilute hydrochloric acid.

162-164℃10,51n'1LHg by distillation
A pale yellow liquid 24.8S' was obtained.

Example 5 Preparation of 1,5-bis(3',5'-di-tert-butyl-4'-hydroxyphenyl)-2,2,4,4-tetramethylpentanone-3 20.6? 2,6-di-tert-butylphenol, 1.7
2 of potassium hydroxide and 60 ml of dimethyl sulfoxide were mixed and heated to 85° C. with stirring.

While stirring at this temperature, 14.2S' 1,5-bis(
(diethylamine)-2,2,4,4-tetramethylpentanone-3 is added dropwise.

After the dropwise addition, stirring was continued at the same temperature for another 24 hours.

After distilling off the solvent under reduced pressure, benzene 1QQmA was added and the mixture was washed with dilute hydrochloric acid.

After distilling off the benzene, it was recrystallized with ingropanol to obtain 20.42 of a white powder with a melting point of 141-143°C.

Example 6 Production of 1,5-bis(3',5'-di-tert-butyl-4'-hydroxyphenyl)-2-,i-thylpentanone-3 In the same manner as in Example 1, methyl ethyl ketone, diethylamine hydrochloride, 1-diethylamine-2-methylbutanone-3 is produced from paraformaldehyde and converted into 2,6-
It was reacted with di-tert-butylphenol in the same manner as in Example 1 to produce 1-(3',5'-di-tert-butyl-4'-hydroxyphenyl)-2-methylbutanone-3.

The butanone obtained here was further reacted with diethylamine hydrochloride and paraformaldehyde in the same manner as in Example 1.
- (3',5'-di-tert-butyl-47-hydroxyphenyl)-2-methyl-5-diethylaminopentanone-3 was synthesized.

9.41 of the obtained pentanone, 5.22 of 2,6-di-tert-butylphenol, some dimethylformamide! 8 to a solution of 0.41 sodium hydroxide powder dissolved in
Add dropwise at 0°C.

After the dropwise addition, the mixture was stirred at the same temperature for 16 hours.

The solvent was distilled off under reduced pressure, 100 ml of benzene was added, and after washing with diluted hydrochloric acid, the benzene was distilled off.

Recrystallization from ethanol gave a white powder with a melting point of 149-151°C.

Claims (1)

[Claims] 1 General formula (wherein R1 represents an alkyl group or a cycloalkyl group,
R2 represents a hydrogen atom, an alkyl group, or a cycloalkyl group) and a compound represented by the general formula (where R3, R4, R
5 each represents a hydrogen atom, a methyl group or an ethyl group. R6 represents an alkyl group having 1 to 4 carbon atoms. R7 and R8 are each an alkyl group, a cycloalkyl group,
(In the formula, R1, A method for producing ketones in which R2, R3, R4, and R5 have the same meanings as described above, and R9 is represented by alkyl having 1 to 4 carbon atoms.