Process for producing epoxycyclododecadiene

Details Process for producing epoxycyclododecadiene Process for producing epoxycyclododecadiene

2000-03-10

2001-01-09

Trinh, Ba K. (Department: 1625)

Organic compounds -- part of the class 532-570 series

Organic compounds

Heterocyclic carbon compounds containing a hetero ring...

Reexamination Certificate

active

06172243

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates a process for producing 1,2-epoxy-5,9-cyclododecadiene by bringing 1,5,9-cyclododecatriene into contact with hydrogen peroxide. Not only 1,2-epoxy-5,9-cyclododecadiene can be used as a resin component of a coating composition, an adhesive or the like because of having an active epoxy group and a carbon-carbon unsaturated bond, but also it is an important compound as an intermediate raw material for synthetic fibers or synthetic resins such as polyamide or polyester because it can easily be introduced, after conversion into cyclododecanone, into the corresponding lactam, lactone or dibasic acid in a known manner.
2. Description of the Related Art
As a process for producing 1,2-epoxy-5,9-cyclododecadiene by bringing 1,5,9-cyclododecatriene into contact with hydrogen peroxide in the presence of an aliphatic carboxylic acid, conventionally known is a process (Japanese Patent Publication JP-B-38-772, Unexamined published Japanese Patent Application JP-A-56-104877) in which formic acid and/or halogenoacetic acid is used in a catalytic amount relative to hydrogen peroxide. As a result of the follow-up test of the above-described invention, the present inventors have found that the process is accompanied with such drawbacks as markedly low selectivity to 1,2-epoxy-5,9-cyclododecadiene based on the consumption amount of hydrogen peroxide and necessity of long hours for completion of the reaction.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an industrially desirable process for producing 1,2-epoxy-5,9-cyclododecadiene by bringing 1,5,9-cyclododecatriene into contact with hydrogen peroxide, which process permits production of 1,2-epoxy-5,9-cyclododecadiene with good -selectivity and facilitates control of reaction including shortening of reaction time.
The object of the present invention is attained by a process for producing 1,2-epoxy-5,9-cyclododecadiene by bringing 1,5,9-cyclododecatriene into contact with hydrogen peroxide in the presence of a carboxylic acid having an acid dissociation constant K at 25° C. of 5.0×10
−6
≦K≦1.0×10
−4
.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will hereinafter be described more specifically.
Examples of the carboxylic acid usable in the reaction of the present invention include aliphatic carboxylic acids, alicyclic carboxylic acids and aromatic carboxylic acids each having an acid dissociation constant K at 25° C. of 5.0×10
−6
≦K≦1.0×10
−4
, of which the aliphatic carboxylic acids, alicyclic carboxylic acids and aromatic carboxylic acids each having 2 to 8 carbon atoms and an acid dissociation constant K at 25° C. of 5.0×10
−6
≦K≦1.0×10
−4
are preferred.
Use of carboxylic acids having an acid dissociation constant K greater than 1.0×10
−4
deteriorates the selectivity to 1,2-epoxy-5,9-cyclododecadiene, the target product. When those having an acid dissociation constant K less than 5.0×10
−6
are used, on the other hand, a reaction-rate lowering tendency is recognized.
Specific examples include, among the compounds described in Kagaku Binran Kiso-hen (
Chemistry Handbook, Basic Course
), 4th Edition, II-317 to II-321, published on Sep. 30, 1993 by Maruzen Co., Ltd., linear or branched aliphatic carboxylic acids such as acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, pivalic acid, hexanoic acid, heptanoic acid and octanoic acid, alicyclic carboxylic acids such as cyclohexylcarboxylic acid and aromatic carboxylic acids such as benzoic acid. Preferred are acetic acid and propionic acid. These carboxylic acids may be used either singly or in combination.
Although the carboxylic acid can be added in an amount of at least 0.5 mole per mole of the charged amount of hydrogen peroxide without any particular problem in the reaction of the present invention, an amount of 1 to 50 moles is preferred, with an amount of 2 to 30 moles being more preferred. When the carboxylic acid is added in an amount less than 0.5 mole, it takes a long period of time to complete the reaction and at the same time, a lowering tendency of the selectivity to the target product is recognized. An excessively large amount is, on the other hand, not economical, because it takes much energy to separate the carboxylic acid.
Although there is no limitation imposed on the concentration of hydrogen peroxide to be used in the reaction of the present invention, a 10 to 70 wt. % aqueous solution is preferred in consideration of handling safety and economy. It is used in an amount of 0.05 to 1.2 moles, preferably 0.1 to 1.0 mole, more preferably 0.25 to 1.0 mole per mole of 1,5,9-cyclododecatriene.
As 1,5,9-cyclododecatriene to be used in the present invention, a commercially available one can be used as it is or after purified once.
In the present invention, the reaction proceeds no matter whether the mixture upon reaction is a homogeneous system or a heterogeneous system, but the former is preferred.
The term “homogeneous system” means a system wherein the catalyst, reaction substrate and reaction mixture are not separated into two phases during reaction, which however largely depends on the reaction temperature.
In the reaction according to the present invention, the water content in hydrogen peroxide to be used or water content produced by epoxidizing reaction has a large influence on the results of the reaction, that is, selectivity, reaction rate and operability of reaction. It is preferred to remove, during reaction, water in the reaction system as much as possible in order to make the reaction system homogeneous. More specifically, the reaction system adjusted to have a water content of 20 wt. % or less, preferably 15 wt. % or less, more preferably 10 wt. % or less based on the total weight of the reaction system is preferred.
An excessively large amount of water in the reaction system deteriorates the selectivity to 1,2-epoxy-5,9-cyclododecadiene, the target product.
There is no particular limitation imposed on the method for removing the water content during reaction. Examples include the method to remove the water content by circulating an inert gas with water being adsorbed thereto and the method to separate out water by azeotropy with an ester compound such as ethyl propionate or an aromatic hydrocarbon such as benzene or toluene.
Alternatively, an organic solvent can be used to obtain a homogeneous reaction system. No particular limitation is imposed on the organic solvent insofar as it doesn't inhibit the reaction. Examples include ether compounds such as diethyl ether and dioxane and aliphatic carboxylates such as ethyl acetate and ethyl propionate. These solvents may be used either singly or in combination. The solvent is preferably used in an mount of 0 to 5 times the weight, more preferably 0 to 3 times the weight of 1,5,9-cyclododecatriene.
There is no particular limitation imposed on the reaction of the present invention insofar as it is effected under conditions capable of keeping the homogeneous reaction system during reaction. The reaction is conducted, for example, by mixing 1,5,9-cyclododecatriene, hydrogen peroxide and an aliphatic carboxylic acid in an inert gas atmosphere at normal pressure or under pressure and a reaction temperature of, preferably, 20 to 150° C., more preferably 50 to 130° C. The reaction mixture thus obtained can be isolated or purified by the ordinary method such as distillation.
When, upon conducting the reaction of the present invention, there is a fear of a metal ion or a strong acid, which accelerates decomposition of hydrogen peroxide or ring opening of the epoxy ring of the target product (1,2-epoxy-5,9-cyclododecadiene), being mixed in the reaction system, it is preferred to add a chelating agent such as ethylenediaminetetraacetic acid, a phosphate salt such as sodium pyrophosphate or sodium monohydrogenphosphate, a phosphate ester such as diethylhexyl phospha

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