JPS5844664B2 - 2,4-dimethyl-4-vinyl-1-cyclohexene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides novel 2,4-dimethyl-4-vinyl-1-
This invention relates to a method for producing a cyclohexene maleic anhydride adduct.

2 4-cymef-4-hinyl-1-cyclohexene is a compound represented by the general formula.

Thermal addition reactions of maleic anhydride to cyclic compounds containing two or more non-conjugated double bonds have been studied for a long time, such as the addition of limonene and maleic anhydride or the addition of cyclododecatriene and maleic anhydride. There is.

In addition to the 1:1 adduct of the substrate and maleic anhydride, the reaction products in these maleic anhydride addition reactions include:
It is known that a polyadduct with a slightly larger molecular weight, in which 2 moles or more of maleic anhydride is added, is formed at the same time.
Generally, the amount produced is larger than that of the adduct, and it is known that it is extremely difficult to produce only the 1:1 adduct with good selectivity.

As a result of detailed research on the addition of various compounds and maleic anhydride, the present inventors found that 24-:
'Methyl-4-vinyl-1-cyclohexene (DMVC
We have discovered a new compound which is the reaction product of H) and maleic anhydride.

Moreover, it has been found that a 1:1 adduct can be produced with good selectivity as this reactive component.

Although the reason for this is not necessarily clear, it is presumed to be due to the effect of the substituted methyl group.

That is, 2,4-dimethyl- which is the starting material of the present invention
When vinylcyclohexene, which has a structure similar to 4-vinyl-1-cyclohexene (DMVCH) (the only difference is that there is no methyl group), is reacted with maleic anhydride, 1
: A large amount of polyadducts containing 2 moles or more of maleic anhydride are produced than 1 adduct. From the above, the characteristics of the present invention are that the results are significantly different from the results obtained by the reaction of conventionally known cyclic compounds with maleic anhydride. It can be said that they are different.

The object of the present invention is to provide 2,4-dimethyl-4-vinyl-1-
The purpose of the present invention is to provide a method for producing a 2,4-dimethyl-4-vinyl-1-cyclohexene-maleic anhydride adduct using cyclohexene (hereinafter abbreviated as DMVCH) as a starting material, particularly 2,4-dimethyl-4-vinyl- The present invention provides a method for producing 1-cyclohexenyl succinic anhydride.

The present invention is distantly related to the above-mentioned objects, and has 2.4
A 2,4-dimethyl-vinylcyclohexene-maleic anhydride adduct is produced by reacting -dimethyl-4-vinyl-1-cyclohexene with maleic anhydride.

In the present invention, 1 mol of maleic anhydride is added to 1 mol of DMVCHI.
When moles are added, it is a 1:1 adduct.

2.4-Dimethyl-4-vinyl-1-cyclohexenyl succinic anhydride, a new compound is obtained.

As mentioned above, in the addition of DMVCH and maleic anhydride, maleic anhydride is bonded to the 6- and 3-positions of the cyclohexene ring of DMVCH, but a mixture of a 6-position adduct and a 3-position adduct is usually obtained. .

The ratio between the two can be changed arbitrarily.

As other adducts, 1 mol of maleic anhydride was added to 2 mol of DMVCH.

For example, an adduct having the structure shown below is further added to obtain a copolymer having the structure shown below.

DMVCH, which is a raw material of the present invention, can be easily obtained by thermal dimerization reaction of isoprene or catalytic trimerization reaction using a transition metal catalyst.

In the trimerization of isoprene, generally the chain dimer 2,
6-dimethyl-1,3,6-octatriene (DM
(abbreviated as OT) and a cyclic dimer DMVCH are produced.

The present invention utilizes a cyclic dimer among the above isoprene dimers.

The maleic anhydride used in the present invention may be a commercially available product, but it is particularly good to use one purified by distillation, recrystallization, etc.

The reaction temperature between DMVCH and maleic anhydride is 150~
It is carried out at around 250℃, but if the temperature is too low, the reaction will be slow.
Also, since it is not desirable to have too high a temperature, generally 17
It is desirable to carry out the heating in the range of 0 to 220°C.

The reaction is preferably carried out for a relatively long period of time, and there are no particular restrictions on the reaction time, but it is effective and practical to carry out the reaction for about 1 to 30 hours, preferably about 5 to 25 hours.

Generally, if the reaction time is long, the reaction is carried out at a low temperature, and if the reaction time is short, the reaction is carried out at a high temperature.

In the present invention, DMVCH and maleic anhydride can be reacted as they are, but if necessary, a suitable organic solvent can be used.

When selecting a solvent, it is necessary to use one that does not react with maleic anhydride. As this type of solvent, aromatic hydrocarbons such as benzene, toluene, and xylene can be used, but ethers such as dioxane, tetrahydrofuran, and ethyl ether can be used. You can also use

The amount of solvent is not particularly limited, but it is preferably used in a molar ratio of about 15 times or less to the maleic anhydride charged.

A larger amount is inconvenient and uneconomical.

The reaction pressure may be at least normal pressure, usually from normal pressure to about 10K.
It is preferable that it is g/-.

A general reaction device can be used as the reaction device, but
Particular preference is given to using an autoclave.

If an autoclave is used, it is easy to heat the mixture of the above raw materials and solvent of the present invention to around 200'C.

The molar ratio of DMVCH to maleic anhydride is not particularly limited, but is preferably in the range of about 10:1 to 1:10.

When there is a large amount of DMVCH, a 1:1 adduct is mainly produced, and in this case, the excess DMVCH is considered to play the role of a solvent.

Furthermore, when maleic anhydride is in excess, polyadducts are produced in addition to the 1:1 adduct.

When carrying out the above reaction, the air in the autoclave can be replaced with an inert gas such as nitrogen, if necessary.

Further, it is preferable to use a small amount of a phenol compound or an amine compound such as 2,6-di(t-butyl)-p-cresol or phenyl-β-naphthylamine as an antioxidant.

In carrying out the present invention, although a catalyst is not necessarily required, para-toluenesulfonic acid, sulfuric acid, phosphoric acid, zinc chloride, and similar substances thereof may be added as a catalyst in an amount of about 0.1 to 10% by weight based on DMVCH. You can also do it.

In the production method of the present invention, purely isolated DMVCH and maleic anhydride may be reacted, but a mixture with other reactive compounds such as DMOT can be directly subjected to the maleic anhydride addition reaction.

For example, DMVC produced by isoprene dimerization reaction
By adding maleic anhydride in an amount equal to or more than DMOT to a mixture of H and DMOT and heating and stirring the mixture as it is or in the presence of a solvent such as benzene at 150 to 250°C, the novel compound of the present invention, especially 1 :1 adduct is DMO
Produced together with T-maleic anhydride adduct, DMOT
- The maleic anhydride adduct can be easily separated and removed from the target product by distillation.

Another method is to use a mixture of DMVCH and DMOT.
By stirring with maleic anhydride at a temperature of about 0 to 70°C for about 2 hours, DMOT and maleic anhydride can be easily separated.
Since a 1:1 adduct (liquid) is produced by the Ziels-Alder reaction, unreacted DMVCH is separated and recovered from the reaction product (adduct of DMOT and maleic anhydride) by distillation, and this is further purified. The target compound of the present invention can be obtained by heating and stirring at 150 to 250°C in the presence of maleic anhydride.

After the heating reaction between DMVCH and maleic anhydride is completed, the solvent and unreacted substances are removed from the reaction solution to obtain a brown product mixture.

By distilling this product under reduced pressure, 2.4-dimethyl-4-vinyl-1-cyclohexenylsuccinic anhydride is obtained.

According to the process of the present invention, as the main product, 1:1 DM
The above compound (pale yellow, slightly viscous liquid, molecular weight 234) which is the reaction product of VCH and maleic anhydride is obtained.

Together with this main component, an adduct compound having a molecular weight of about 300 to 1,000 and generally solid at room temperature is obtained, but this polyadduct can be separated as a bottom residue.

The DMVCH-maleic anhydride adduct obtained by the production method of the present invention can be used for various purposes, and in particular, the 1:1 substituted product has characteristics such as being liquid and having a vinyl group. Therefore, it is extremely useful as a raw material for alkyd resins and polyesters, for example.

It is also extremely useful as a pigment dispersant and epoxy curing agent.

Furthermore, it is extremely useful as a raw material for half-esterification of anhydrous substances, diesterization, dicarboxylic acid chloride, etc., and those with halogenated unsaturated double bonds are useful as raw materials for flame-retardant resins or insecticides.

In addition, a small amount of polyadduct produced together with the 1:1 adduct is
It is not necessary to separate it from the 1:1 adduct of DMVCH, and the reaction crude product can be used as it is in the above-mentioned applications, if desired.

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

Example 1 145 g of maleic anhydride and 40:1 of 2,4 dimethyl-4-vinyl-1-cyclohexene were added to a 51 autoclave (1), and after purging with nitrogen, the autoclave was stirred at 200° C. for 10 hours.

At this time, the reaction pressure was about 5 kg/-.

After cooling to room temperature, unreacted monomers were removed by distillation, yielding 258 g of a pale brown crude product.

By distilling this under reduced pressure, it becomes a pale yellow and slightly viscous liquid.
Cyclohexenyl succinic anhydride 174
I got g.

The boiling point of this compound is 127-132°C,'o,
5 mmHg Molecular weight 234: Elemental analysis values were as follows.

CI-■ Theoretical value 71.77% 7.74% Experimental value 71.62% 7.53% The selectivity was 66.6 mol%: the yield was 33.5 mol%.

Example 2 51' maleic anhydride and 165 g of 24 dimethyl-4
- Vinyl-1-cyclohexene was added into a 1.51 autoclave in the same manner as in Example 1, and after nitrogen substitution,
The reaction was carried out at 200°C for 10 hours.

At this time, the reaction pressure was about 10 kg/i.

By the same treatment as in Example 1, 70 g of crude product was obtained.

This was further distilled under reduced pressure to obtain 55 g of 2,4-dimethyl-4-vinyl-1-cyclohexenyl succinic anhydride.

The selectivity was 71.7 mol% and the yield was 278 mol%.

Example 3 98 g maleic anhydride, 27 g 2,4-dimethyl-
4-vinyl-1-cyclohexene, 300 g of benzene was added into the autoclave and 20
As a result of stirring the reaction at 5° C. for 20 hours, 36 g of a pale brown crude product was obtained.

At this time, the reaction pressure was about 10 kg/ffl.

By further distilling this under reduced pressure, 28 g of 2,4-dimethyl-4-vinyl-1-cyclohexenylsuccinin quanhydride was obtained.

The selectivity was 78 mol%; the yield was 60.0 mol%.

Example 4 79 g maleic anhydride, 164 g 2,4 dimethyl-
4-vinyl-1-cyclohexene and 1 g of pt-luenesulfonic acid were added into a 1.51-liter autoclave and heated at 190° C. for 6 hours at a reaction pressure of about 5 kg according to Example 1.
The reaction was carried out at /-.

By the same treatment as in Example 1, 128 g of crude product was obtained.

By further distilling this under reduced pressure, 2゜4-shi)-j
77 g of -4-vinyl-1-cyclohexenyl succinic anhydride was obtained.

The selectivity was 59.5 mol% and the yield was 24.3 mol%.

Example 5 30.9 g maleic anhydride, 165 g 2,4 dimethyl-4-vinyl-1-cyclohexene in 1.54 g
~added in crepe, according to Example 1, 2100
The reaction mixture was heated and stirred at C for 10 hours.

The reaction pressure at this time was about 5 to 9/-. After the reaction is complete,
Unreacted monomers were distilled off to obtain 56 g of crude product.

Further, by distillation under reduced pressure, 46 g of 2゜4-dimethyl-4
46 g of -vinyl-1-cyclohexenyl succinic anhydride was obtained.

The selectivity was 82.0 mol% and the yield was 64.0 mol%.

Example 6 A mixture of 136 g of 24-dimethyl-4-vinyl-1-cyclohexene and 2,6-dimethyl-1,3°6-octatriene (weight ratio 6:4) was dissolved in 500 g of benzene, and 98 g of anhydrous Add maleic acid dropwise.

The above mixture was added to a 1.51 autoclave according to Example 1, and reacted by heating and stirring at 200°C for 20 hours.

145 g of the reaction mixture produced was distilled to give a pale yellow 2,4
-Dimethyl 4-vinyl-1-cyclohexenylsuccinic anhydride (38 g) was obtained.

This selection was 260 mol% and the yield was 16.1 mol%.

In the following examples, 2,4-dimethyl-4vinyl-1-cyclohexenyl succinic anhydride has a succinic anhydride group bonded to the 6-position of the cyclohexene ring, and 2,4-dimethyl-4vinyl-1-cyclohexenyl succinic anhydride group to the 3-position of the cyclohexene ring. The ratio of 6-position adduct/3-position adduct in each example was as follows.

Note that the NMR analysis values of the above adduct are as follows.

NMR:p…(CD(J?3)

Claims (1)

[Claims] 2,4-dimethyl-4-vinyl-1-, characterized in that 124-dimethyl-4-vinyl-1-cyclohexene is reacted with maleic anhydride at 1500C to 250C.
A method for producing a 6- or 3-position maleic anhydride adduct of cyclohexene.