JPS5850969B2 - Manufacturing method of hexamethyltetralin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention utilizes a novel catalyst system to produce 1,1,3,4,4
゜6-Hexamethyl-1,2,3,4,-tetrahydronaphthalene (general name 1.1.3.4.4.6-hexamethyltetraline, the abbreviation “HMT” may be used in the following explanation) .

), and provides an economical method for producing HMT, which is a precursor of tetralin-based musk perfume, in terms of both raw material supply and cost.

More specifically, the present invention involves reacting P-cymene with 2,3-dimethylbutenes or neohexene to produce 1.1
．． 3.4.4.6-Hexamethyl-1,2,3,4-tetrahydronaphthalene (HMT) is produced by using an organoaluminum compound represented by the general formula AlR3 (where R is an alkyl group) as a catalyst. The present invention relates to a method characterized in that the reaction is carried out in the presence of at least one type of organic halide represented by the following general formulas (I) to (IV).

General formula (I) R2>CH-X (wherein R1 and R2 represent an alkyl group, and X represents R1\halogen atom.

). General formula (I) R2-C-XR3/ (where RI R2R3 represents an alkyl group, and X represents a halogen atom.

). General formula (III) HC=c -CH2-X (however,
X represents a halogen atom.

). General formula (fV) CH, =CH-CH2-X (however,
X represents a halogen atom.

). A variety of synthesis methods have been proposed for tetralin-based musk, which has traditionally replaced natural macrocyclic ketone-based musk fragrances due to its superior quality and retention properties, and various proposals have also been made regarding its precursor, HMT. .

However, when these prior art techniques are examined in detail, they have the following drawbacks, and it is difficult to say that they are perfect from a technical and economic standpoint.

According to U.S. Pat. No. 2,759,022, it is proposed to obtain a product from P-cymene and methyl-t-butylcarbinol using a sulfuric acid catalyst, which is then isolated and acetylated to obtain a musk aroma substance. However, there is no description of the product structure or yield, making it difficult to make a technical evaluation.

U.S. Pat. No. 2,851,501 proposes that a musk aroma substance can be obtained by acetylating the product obtained by reacting α-P-dimethylstyrene and 2,3-dimethylbutenes in acetic acid with a fine acid catalyst. However, the structure of the product is an indane structure, which is different from HMT in the present invention.

U.S. Pat. No. 3,278,624 proposes a method for obtaining HMT from α,P-dimethylstyrene and dimethyl-i-propylcarbinol or methyl-t-butylcarbinol in acetic acid using sulfuric acid as a catalyst. However, there is no mention of yield.

All of the above three methods use a large excess of concentrated sulfuric acid, leading to corrosion of the reaction equipment and complicated post-reaction treatment.

U.S. Patent No. 3,379,782 and Dutch Patent No. 6
, No. 612,053, it is proposed to obtain HMT by reacting α,P-dimethylstyrene and 2,3-dimethylbutenes using activated clay or an ion exchange resin as a catalyst, but this method has a one-pass conversion rate. It is necessary to recover and use unreacted olefin, and α,P-dimethylstyrene is difficult to obtain and is an expensive raw material, so it lacks economic efficiency.

British Patent No. 987.747 describes 2-rioo-2-(p
-Tolyl)propane and neohexene are reacted using a Friedel-Craft type catalyst to obtain HMT, and British Patent No. 1,442,954 describes the presence of P-cymene, neohexene, and tertiary alkyl halide in the presence of an aluminum halide catalyst. A technique has been proposed to obtain HMT by reacting the aluminum halide with aluminum, which is an excellent method with a high yield of HMT, but because the catalyst, aluminum halide, is solid and sensitive to moisture, the method for storing and preparing it is complicated. Moreover, during the reaction, due to the heterogeneous dispersion state, the catalyst scatters and adheres to the vessel wall and the reaction is localized, resulting in a lack of constancy of the reaction and quantitative determination of the catalyst.

The present inventors have invented a method for inexpensively synthesizing 2,3-dimethylbutenes by trimerizing propylene, and a separate application is currently being filed. By using a liquid homogeneous catalyst called proprietary aluminum, we have been actively investigating whether there is an economical method for producing HMI' that would improve the shortcomings of the prior art. The present invention was achieved by discovering the fact that HMT can be obtained in high yield from 3-dimethylbutenes and active organic halides.

Furthermore, it has been found that the method of the present invention provides a high yield of HMT even when neohexene is used in place of 2,3-dimethylbutenes, and the present invention also includes this method.

According to the method of the present invention, an inexpensive and stable supply system is established 2.
H by an economical method using 3-dimethylbutenes
It has the characteristics of being able to produce MT and also being applicable to neohexene, which has a certain supply system.At the same time, since a liquid organoaluminum compound is used as a catalyst, the reaction proceeds in a nearly homogeneous system, and Since the weighing and charging of the catalyst can be carried out in the form of a solution, it has the characteristics of excellent quantitative performance and easy control.

The organoaluminum compound used in the present invention has the general formula AA
It is trialkylaluminum represented by R3 and is a liquid substance.

Although it reacts violently when it comes in contact with oxygen or water, Ziegle
It is widely used in r-type catalysts, etc., and can be handled safely and quantitatively by those familiar with the technology.

Typical compound names include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-1so-propylaluminum, tri-n-butylaluminum, l! Examples include trialkylaluminum such as J-iso-butylaluminum and tri-n-hexylaluminum.

As the raw material olefin 2,3-dimethylbutenes, both 2,3-dimethyl-1-butene and 2゜3-dimethyl-2-butene can be used, but from the viewpoint of HMT yield, 2.
, 3-dimethyl-1-butene is preferably used.

Also, neohexene can be preferably used as a raw material olefin, resulting in a high HMT yield.

Next, as active organic halides, general formulas (I) to (I
A compound represented by V) is used, but from the viewpoint of HMT yield and by-products, a tertiary halide represented by formula (n) is preferably used.

Representative examples of compounds represented by these general formulas are listed below.

As the secondary halide represented by general formula (I), 1
Examples include so-propyl chloride, SeC-butyl chloride, SeC amyl chloride, cyclohexyl chloride, and analogues thereof in which C1 is replaced with a halogen atom such as F Br I.

As the tertiary halide of general formula (II), tert
-butyl chloride, tcrt-amyl chloride, 2
-Methyl-2-ruhentane, 3-methyl-3-chlorobencune, and their analogues in which CA is substituted with a halogen atom such as F Br I are listed.

The propargyl halide of general formula (IID is propargyl chloride, and these CA? are F, Br, I
Homologues substituted with the same halogen atom are listed.

The reaction is generally carried out in a solvent, but the reaction can also be carried out without a solvent by using an excess of P-cymene, one of the raw materials.

As a reaction catalyst, aliphatic hydrocarbons such as n-hexane, n-\butane, cyclohexane, chlorobenzene, O-
Halogenated aromatic hydrocarbons such as dichlorobenzene, frombenzene, fluorobenzene, methylene chloride, chloroform, carbon tetrachloride, ethylene chloride, ethylidene chloride, 1,1.1-4lychloroethane, 1.1.2-tI
J Chlorethane, 1,1,2.2-tetrachloroethane, 1,2-dichloroethylene, trichlorethylene,
Examples include halogenated aliphatic hydrocarbons such as tetrachloroethane, 1,2,3-toIJ chloropropane, amyl chloride, and ethylene tribromide.

In preferred practice of the method of the present invention, P-cymene is
The active organic halide is preferably used in an amount equal to or more than 2 times the mole relative to 2,3-dimethylbutenes or neohexene, and the active organic halide is preferably used in an equal mole or more relative to 2,3-dimethylbutenes or neohexene. Among them, the yield of HMT for relatively expensive olefins (2,3-dimethylbutenes or neo\xeno) is increased.

The organoaluminum compound as a catalyst may be used in a catalytic amount, and is used in an amount of about 1 to 20 moles φ relative to 2,3-dimethylbutenes or neohexene as a raw material olefin.

There is no particular restriction on the reaction temperature, but it is generally between -30°C and 5°C.
It is carried out at 0°C, preferably in the range of -10°C to 20'C.

If the temperature is too low, the reaction rate will decrease, and if the temperature is too high, 50°C or higher, side reactions will occur.

However, this optimum range varies depending on the type of organoaluminium and solvent used.

According to the method of the present invention, the theoretical yield of HMT based on 2,3-dimethylbutenes or neohexene is 30% or more, and in some cases shows a high yield of 50% or more.

The method of the present invention will be specifically explained below with reference to Examples.
The present invention is not limited to these.

Example 1 After purging a 500mm round bottom flask equipped with a dropping funnel, condenser, and stirrer with nitrogen, 0.0% of triethylaluminum was added.
Chlorobenzene solution containing 015 mol 10TIl11
Charge 30Wll of chlorobenzene.

Then P-Cymene 8 (15 g of 1,2,3-dimethyl-1-butene and 19.8 g of tert-butyl chloride
The mixture was added dropwise to react at -5°C for 2 hours.

After completion of the reaction, the reaction solution is poured into drained water to stop the reaction, and the oil layer is washed with 5-predominant soda and then with water, separated, and dried with sodium sulfate.

The reaction solution is first distilled at atmospheric pressure to remove the solvent and unreacted P-cymene, and then vacuum distilled.

2 as a fraction with a boiling point of 104-107°C/3.5 H2
1.1g was obtained.

Results of gas chromatograph analysis, 1.1.3.4
．． The purity was 95φ as 4,6-hexamethyl-1°2,3,4-tetrahydronaphthalene (HMT).

Melting point -58°C. The HMT yield in terms of purity is the 2,3-
It was 52 mounds for dimethyl-1-butene.

The distilled HMT was then recrystallized from an equal amount of isopropyl alcohol to obtain pure HMT with a melting point of 67°C.

As a result of gas chromatograph analysis, HMT purity was 98.
He was in charge.

The results of infrared absorption and NMR analysis are from separately synthesized standard sample 1.
．． 1.3.4゜4.6-'\xamethyl-1.2.3.
It was consistent with 4-tetrahydronaphthalene.

Acetylation was performed using the purified HMT as follows.

After replacing the 2001nl flask with a condenser with nitrogen,
10 g of HM7r, 4 g of acetyl chloride, and 40.9 g of dichloroethane were charged. While stirring with a Miteflon-coated magnetic cooler, 7.4 g of anhydrous powdered aluminum chloride was charged in 6 portions at 20°C.
The reaction was allowed to proceed for 5 hours.

After the reaction is completed, the reaction is stopped by pouring the reactants into 50 g of water, washed twice with 50% aqueous soda water, then twice with water, and dried over sodium sulfate.

After distilling off the solvent dichloroethane at normal pressure, vacuum distillation was performed to reduce the boiling point to 145-150°C/2m71II-(g of fraction to 11
I got g.

Melting point: 52.5°C. Further recrystallization from an equal volume of ethanol at 10°C gave a white solid with a strong musky odor.

Melting point = 56°c.

As a result of gas chromatograph analysis of this product, purity is 9.
8, and the results of infrared absorption and NMR analysis show that the standard is 7.
-acetyl-1,1,3,4,4,6-hexamethyl-
Consistent with 1,2,3,4-tetrahydronaphthalene.

Example 2 Same as Example-1 except that 15g of Neo\xeno was used instead of 2,3-dimethyl-1-butene in Example-1.
The experiment was conducted in exactly the same way.

Boiling point 105-108 °C / 3.5 as a Hg fraction 2
6 g of white solid was obtained.

Melting point = 59°C. Gas chromatograph analysis results 1
．． 1.3.4.4.6-hexamethyl-1,2,3,4
- Purity as tetrahydronaphthalene (HMT) = 96
%Met.

The HMT yield in terms of purity is 6 based on the raw material neohexene.
It was 5φ.

Then, it was recrystallized from an equal amount of isopropyl alcohol to obtain pure white HMT with a melting point of 267°C.

As a result of analysis by gas chromatography, the purity was 98.

Acetylation was carried out in the same manner as in Example 1 to obtain 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene having a strong musky odor.

Example 3 iq substituted for ter-butyl chloride in Example 1
An experiment was carried out in exactly the same manner as in Example 1, except that a predetermined amount of the organic halide shown in 1 was used.

The results obtained are shown in Table-1.

Example 4 In Example 1, triethylaluminum was added to 0.015
Instead of 10wLl of chlorobenzene containing mol and 40m of additional chlorobenzene, 50Tl of each solvent shown in Table-2
The experiment was carried out in exactly the same manner as in Example 1, except that 0.015 mol of triethylaluminum was dissolved in 1 ml, and the results shown in Table 2 were obtained.

Note that /f65 in Table 2 is obtained by charging 0.015 mol of triethylaluminum dissolved in 10 Tll of P-cymen, which is a part of the monomer, into a flask and then reacting without using a solvent.

Example 5 Table 3 was used instead of monochlorobenzene in Example 2.
The experiment was carried out in exactly the same manner as in Example 2, except that 0.015 mol of triethylaluminum was dissolved in 501 rLl of the solvent shown in .

The results obtained are shown in Table 3.

Claims (1)

[Claims] 1. 1.1.3.4.4.6-hexamethyl-1,2,3,4, by reacting P-cymene with 2,3-dimethylbutenes or neo\xane - In a method for producing tetrahydronaphthalene, general formula 1? It is characterized by using a catalytic amount of trialkylaluminum represented by R3 (where R is an alkyl group) and reacting it in the presence of at least one organic halide represented by the following general formulas (I) to (IV). How to do it. 2R1\ class halide represented by the general formula (I) )R2-C-X (However, R3/R1, R2, R3 represent an alkyl group, and X represents a halogen atom.) A tertiary halide represented by the general formula (IIOHC
...Propargyl halide represented by C-CH2-X (wherein, X represents a halogen atom). An allyl halide represented by the general formula (IV) CH2CH-CH2X (wherein, X represents a halogen atom).