JPH08176140A - 5-methylene-1,3-dioxane-4,6-dione derivative, method for synthesizing the same and method for stabilizing the same - Google Patents

Abstract

PURPOSE: To obtain a new compound useful as a polymerizable monomer used for synthesis of coating, adhesive, etc. CONSTITUTION: This compound is expressed by formula I (R1 and R2 are each an organic group having C or R1 and R2 may together form a ring, with the proviso that R1 and R2 are simultaneously not methyl), e.g. 5-methylene-2- methyl-2-ethyl-1,3-dioxane-4,6-dione. The compound of formula I is obtained by reacting 1,3-dioxane-4,6-dione derivative of formula II with paraformaldehyde in the presence of an organic acid (e.g. ice acetic acid) and an organic acid metal salt (e.g. anhydrous acetic acid copper salt) at 30-180 deg.C. The molar ratio of the compound of formula II to paraformaldehyde is (1:1) to (1:5) and the organic acid is used in an amount of 1-10 times by weight based on the compound of formula II and the organic acid metal salt is used in an amount of 0.5-10wt.% of the reaction solution. The compound of formula I has high polymerizability and stably exists in an organic acid of the reaction solution. When the compound is utilized in isolated state, the compound is stabilized by adding an acidic substance (e.g. diphosphoruspentoxide) to the compound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel compound having polymerizability, a method for producing the same, and a method for stabilizing the same, which can be widely used in the chemical industry, paints and adhesives industries.

[0002]

PRIOR ART 5-Methylene-2,2-dimethyl-1,3-dioxane belonging to 5-methylene-1,3-dioxane-4,6-dione derivative
-4,6-dione has been studied by various synthetic methods as an intermediate or an active intermediate for producing a drug, but the reactivity of the compound itself is remarkably high as an active intermediate, Although the precursor was obtained, the compound could not be isolated and utilized.

For example, in US Pat. No. 5,243,053,
Disclosed are salts of respective bases in which the 5-position of Meldrum's acid (2,2-dimethyl-1,3-dioxane-4,6-dione) is substituted with pyridine, piperidine and morpholine as stable precursors of methylene Meldrum's acid. However, it has not been isolated.

Further, 5-methylene-2,2-dimethyl-1,3-dioxane-4,6-dione is 2,2-dimethyl-1,3-dioxane-4,6-
The fact that dione or diisopropylidene methylene dimalonate and a 37% aqueous formaldehyde solution are reacted at room temperature has been proved by capturing the compound with a reactive diene such as butadiene or isoprene ( Tetrahedron Letter, 26,3195
(1985)).

Furthermore, 5-methyl-1,3-dioxane-2,2-dimethyl-4,6-dione is reacted with phenylselenyl bromide to give 5-methyl-5-phenylselenyl-1,3-dioxane.
-2,2-Dimethyl-4,6-dione, and then from -78 ℃ 2
There is also an example in which methylene Meldrum's acid is generated by oxidation with p-chloroperbenzoic acid in a temperature range of 0 ° C. and captured by cyclopentadiene or the like (Austral J. Chem.,
30 179 (1977)).

[0006]

DISCLOSURE OF THE INVENTION The present inventors have found that the 5-methylene-1,3-dioxane-4,6-dione derivative is a compound having a double bond and a cyclic structure. It was judged as promising as a polymerizable compound (monomer) used for modification and improvement of the like, and 5-methylene-1,3-dioxane-4,
We isolated and acquired 6-dione derivatives and investigated whether they could be applied to those applications.

[0007]

[Means for Solving the Problems] Therefore, the present inventors
For the purpose of obtaining a methylene-1,3-dioxane-4,6-dione derivative, various investigations were conducted on the production method and the reactivity of the compound, and according to the specific production method,
That these derivatives can be obtained, and that 5-methylene-
The reactivity of 5-methylene-1,3-dioxane-4,6-dione derivatives other than 2,2-dimethyl-1,3-dioxane-4,6-dione can be controlled by the addition of acidic substances, therefore The inventors have completed the present invention by discovering that their derivatives can be isolated and used, and that they have excellent polymerizability as expected.

That is, the present invention relates to a 5-methylene-1,3-dioxane-4,6-dione derivative represented by the general formula (1),

[0009]

Embedded image

(In the formula, R ₁ and R ₂ are organic groups containing a carbon atom, and they may be bonded to each other to form a cyclic structure, but both are not methyl groups.)

It is characterized in that paraformaldehyde is reacted with a 1,3-dioxane-4,6-dione derivative represented by the general formula (2) in the presence of an organic acid and an organic acid metal salt.
An invention relating to a method for synthesizing a 5-methylene-1,3-dioxane-4,6-dione derivative,

[0012]

[Chemical 4]

(R ₁ and R ₂ in the formula are defined in the same manner as in the above general formula (1).)

The invention relates to a method for stabilizing a 5-methylene-1,3-dioxane-4,6-dione derivative, which is characterized in that it is stabilized by the addition of an acidic substance.

The details of the 5-methylene-1,3-dioxane-4,6-dione derivative of the present invention, its synthetic method and its stabilizing method will be described below.

<5-Methylene-1,3-dioxane-4,6-dione derivative> The 5-methylene-1,3-dioxane-4,6-dione derivative of the present invention is represented by the above general formula (1). Wherein R ₁ and R ₂ are organic groups containing a carbon atom and may be bonded to each other to form a cyclic structure, but both are not methyl groups. Is. Examples of the organic group containing a carbon atom include an alkyl group, an alkoxyalkyl group, an aralkyl group, a cycloalkyl group, an alkenyl group and an aryl group. Among them, the organic group preferable for the present invention is an alkyl group which may be substituted with hydrogen, from the viewpoint of easiness of synthesis, and particularly, an alkyl group which may have a substituent having 1 to 6 carbon atoms and the alkyl group to which they are bonded. It is an alkylene group. Note that R _1, R ₂ in the formula constitute a to cyclic structures bond, R _1,
R ₂ is an alkylene group, which means that they are combined to form a ring.

Specific examples of the 5-methylene-1,3-dioxane-4,6-dione derivative include 5-methylene-2-methyl-2-ethyl.
-1,3-dioxane-4,6-dione, 5-methylene-2,2-diethyl-1,3-dioxane-4,6-dione, 5-methylene-2-methyl-
2- (n-propyl) -1,3-dioxane-4,6-dione, 5-methylene-2-methyl-2- (iso-propyl) -1,3-dioxane-4,6-dione, 5- Methylene-2,2-pentamethylene-1,3-dioxane
-4,6-dione, 5-methylene-2-methyl-2- (n-butyl) -1,3-
Dioxane-4,6-dione, 5-methylene-2-methyl-2- (iso-
Butyl) -1,3-dioxane-4,6-dione, 5-methylene-2-methyl-2- (tert-butyl) -1,3-dioxane-4,6-dione, 5-
Methylene-2-ethyl-2- (n-propyl) -1,3-dioxane-4,
6-dione, 5-methylene-2-ethyl-2- (isopropyl) -1,3-
Dixane-4,6-dione, 5-methylene-2,2-hexamethylene
-1,3-dioxane-4,6-dione, 5-methylene-2-methyl-2-
(n-amyl) -1,3-dioxane-4,6-dione, 5-methylene-2
-Methyl-2- (iso-amyl) -1,3-dioxane-4,6-dione,
5-methylene-2-ethyl-2- (n-butyl) -1,3-dioxane-4,
6-dione, 5-methylene-2-ethyl-2- (iso-butyl) -1,3-
Dioxane-4,6-dione, 5-methylene-2-ethyl-2- (tert
-Butyl) -1,3-dioxane-4,6-dione, 5-methylene-2,2
-Di (n-propyl) -1,3-dioxane-4,6-dione, 5-methylene-2,2-di (iso-propyl) -1,3-dioxane-4,6-dione, 5-methylene -2,2-heptamethylene-1,3-dioxane-
4,6-dione, 5-methylene-2-methyl-2- (n-hexyl) -1,3
-Dioxane-4,6-dione, 5-methylene-2-ethyl-2- (n-
Amyl) -1,3-dioxane-4,6-dione, 5-methylene-2- (i
so-propyl) -2-methyl-2-phenyl-1,3-dioxane-4,
6-dione, 5-methylene-2,2-octamethylene-1,3-dioxane-4,6-dione, 5-methylene-2-methyl-2- (n-heptyl) -1,3-dioxane-4 , 6-dione, 5-methylene-2,2-di (n
-Butyl) -1,3-dioxane-4,6-dione, 5-methylene-2,2
-Di (iso-butyl) -1,3-dioxane-4,6-dione, 5-methylene-2,2-di (sec-butyl) -1,3-dioxane-4,6-dione, 5-methylene -2,2-di (tert-butyl) -1,3-dioxane-
4,6-dione, 5-methylene-2,2-nonamethylene-1,3-dioxane-4,6-dione, 5-methylene-2-methyl-2- (n-nonyl)-
1,3-dioxane-4,6-dione, 5-methylene-2,2-di (n-amyl) -1,3-dioxane-4,6-dione, 5-methylene-2,2-dione
(iso-amyl) -1,3-dioxane-4,6-dione, 5-methylene
-2,2-di (tert-amyl) -1,3-dioxane-4,6-dione, 5-
Methylene-2-methyl-2- (n-decyl) -1,3-dioxane-4,6-
Dione, 5-methylene-2-methyl-2- (n-undecyl) -1,3-
Dioxane-4,6-dione, 5-methylene-2-methyl-2- (n-dodecyl) -1,3-dioxane-4,6-dione, 5-methylene-2-cyanomethyl-2-phenyl-1, 3-dioxane-4,6-dione, 5
-Methylene-2-methyl-2- (p-cyanophenyl) -1,3-dioxane-4,6-dione, 5-methylene-2-methyl-2- (3-cyanopropyl) -1,3-dioxane -4,6-dione, 5-methylene-2- (t
ret-Butyl) -2-cyanomethyl-1,3-dioxane-4,6-dione, 5-methylene-2,2-diphenyl-1,3-dioxane-4,6-
Dione, 5-methylene-2-methyl-2-trifluoromethyl-1,3
-Dioxane-4,6-dione, 5-methylene-2-methyl-2- (2-
Ethoxyethyl) -1,3-dioxane-4,6-dione, 5-methylene-2-methyl-2- (2-methoxy-2,2-dimethyl) ethyl-1,
3-dioxane-4,6-dione, 5-methylene-2-methyl-2-ethoxycarbonylmethyl-1,3-dioxane-4,6-dione,
5-methylene-2-ethyl-2-ethoxycarbonylmethyl-1,3
-Dioxane-4,6-dione, 5-methylene-2-methyl-2- (3-
Examples include chloropropyl) -1,3-dioxane-4,6-dione, but the present invention is not limited thereto.

5-methylene-1,3-dioxane-4,6-of the present invention
A dione derivative is a compound that is extremely easily polymerized, and when it is contacted with an alkaline substance such as sodium hydroxide, potassium hydroxide, pyridine, or piperidine, it becomes a resinous substance with remarkable heat generation, and even if it is a very weak nucleophilic substance such as water. It instantly polymerizes to form a resinous material. Also,
As will be described later, the rate of polymerization of the derivative by an acidic substance such as hydrochloric acid, nitric acid, phosphoric acid, zinc chloride, iron chloride, boron trifluoride, sulfur dioxide, paratoluenesulfonic acid, benzenesulfonic acid, acetic acid, formic acid, and propionic acid. It is considered that the derivative has anionic polymerizability because it can be delayed or prohibited.

<Method for synthesizing 1,3-dioxane-4,6-dione derivative> 1,3-used in the present invention for synthesizing 5-methylene-1,3-dioxane-4,6-dione derivative Dioxane-4,6
-Dione derivative, and as represented by the general formula (2),
A derivative having a substituent only at the 2-position and a hydrogen atom at the 5-position, which reacts with paraformaldehyde in the presence of an organic acid and an organic acid metal salt to give 5-methylene-1,3-dioxane-
It becomes a 4,6-dione derivative.

As a method for synthesizing the 1,3-dioxane-4,6-dione derivative itself, the following two known methods can be used. One is a method by reacting malonic acid with acetone (J. Chem.
Soc., 93, 598 (1908)) or a method according to the method. That is, when malonic acid and acetone are reacted at room temperature in an acetic anhydride solvent containing sulfuric acid, 2,2-dimethyl-
1,3-dioxane-4,6-dione is obtained, and if other ketones are used instead of acetone, various 1,3-dioxane-4,6
-A dione derivative is obtained. For example, if malonic acid and methyl ethyl ketone are reacted under similar conditions, 2-methyl
2-Ethyl-1,3-dioxane-4,6-dione is obtained.

Meldrum's acid is a solid at room temperature, whereas 2-methyl-2-ethyl-1,3-dioxane-4,6-dione is a liquid. 1,3-dioxane-4,6, including Meldrum's acid
-The dione derivative is vulnerable to heat, and solid ones at room temperature can be easily purified by recrystallization, while liquid ones cannot be purified by general distillation as a liquid purification method. Since there are almost no byproducts in the reaction method, neutralization,
With simple operations such as solvent extraction and solvent distillation, the 5-
As shown in the following examples, the methylene-1,3-dioxane-4,6-dione derivative having a sufficient quality as a starting material can be obtained.

Another method is the reaction of 2,2-dimethyl-1,3-dioxane-4,6-dione obtained as described above with other ketones (Monatshefte fur Chemie 10
7, 317-324 (1976)), 2,2-dimethyl-1,3-dioxane-
By heating 4,6-dione and other ketones, 5-
It is possible to obtain a 1,3-dioxane-4,6-dione derivative which is preferable as a raw material for synthesizing a methylene-1,3-dioxane-4,6-dione derivative.

Specific examples of the 1,3-dioxane-4,6-dione derivative include 2-methyl-2-ethyl-1,3-dioxane-4,6-
Dione, 2,2-diethyl-1,3-dioxane-4,6-dione, 2-
Methyl-2- (n-propyl) -1,3-dioxane-4,6-dione, 2
-Methyl-2- (iso-propyl) -1,3-dioxane-4,6-dione, 2,2-pentamethylene-1,3-dioxane-4,6-dione,
2-methyl-2- (n-butyl) -1,3-dioxane-4,6-dione, 2
-Methyl-2- (iso-butyl) -1,3-dioxane-4,6-dione,
2-methyl-2- (tert-butyl) -1,3-dioxane-4,6-dione, 2-methyl-2- (n-propyl) -1,3-dioxane-4,6-dione, 2- Ethyl-2- (iso-propyl) -1,3-dioxane-4,6
-Dione, 2,2-hexamethylene-1,3-dioxane-4,6-dione, 2-methyl-2- (n-amyl) -1,3-dioxane-4,6-dione, 2-methyl- 2- (iso-amyl) -1,3-dioxane-4,6-
Dione, 2-ethyl-2- (n-butyl) -1,3-dioxane-4,6-
Dione, 2-ethyl-2- (iso-butyl) -1,3-dioxane-4,6
-Dione, 2-ethyl-2- (tert-butyl) -1,3-dioxane-
4,6-dione, 2,2-di (n-propyl) -1,3-dioxane-4,6-
Dione, 2,2-di (iso-propyl) -1,3-dioxane-4,6-dione, 2,2-heptamethylene-1,3-dioxane-4,6-dione, 2-methyl-2- (n-hexyl) -1,3-dioxane-4,6-dione, 2-ethyl-2- (n-amyl) -1,3-dioxane-4,6-dione, 2- (iso-propyl)- 2-Methyl-2-phenyl-1,3-dioxane-4,6-dione, 2,2-octamethylene-1,3-dioxane-4,6-dione, 2-methyl-2- (n-heptyl) -1,3-dioxane-4,6-dione, 2,2-di (n-butyl) -1,3-dioxane
-4,6-dione, 2,2-di (iso-butyl) -1,3-dioxane-4,6
-Dione, 2,2-di (sec-butyl) -1,3-dioxane-4,6-dione, 2,2-di (tert-butyl) -1,3-dioxane-4,6-dione, 2 , 2-nonamethylene-1,3-dioxane-4,6-dione, 2-
Methyl-2- (n-nonyl) -1,3-dioxane-4,6-dione, 2,2
-Di (n-amyl) -1,3-dioxane-4,6-dione, 2,2-di (is
o-amyl) -1,3-dioxane-4,6-dione, 2,2-di (tert-
Amyl) -1,3-dioxane-4,6-dione, 2-methyl-2- (n-
Decyl) -1,3-dioxane-4,6-dione, 2-methyl-2- (n-
Undecyl) -1,3-dioxane-4,6-dione, 2-methyl-2-
(n-dodecyl) -1,3-dioxane-4,6-dione, 2-cyanomethyl-2-phenyl-1,3-dioxane-4,6-dione, 2-methyl-2- (p-cyanophenyl) -1,3-dioxane-4,6-dione, 2-methyl-2- (3-cyanopropyl) -1,3-dioxane-
4,6-dione, 2- (tert-butyl) -2-cyanomethyl-1,3-dioxane-4,6-dione, 2,2-diphenyl-1,3-dioxane
-4,6-dione, 2-methyl-2-trifluoromethyl-1,3-dioxane-4,6-dione, 2-methyl-2- (2-ethoxyethyl)-
1,3-dioxane-4,6-dione, 2-methyl-2- (2-methoxy-
2,2-Dimethyl) ethyl-1,3-dioxane-4,6-dione, 2-
Methyl-2-ethoxycarbonylmethyl-1,3-dioxane-
4,6-dione, 2-ethyl-2-ethoxycarbonylmethyl-1,
3-dioxane-4,6-dione, 2-methyl-2- (3-chloropropyl) -1,3-dioxane-4,6-dione and the like,
The present invention is not limited to these.

<Method for synthesizing 5-methylene-1,3-dioxane-4,6-dione derivative> 5-methylene-1,3-dioxane-4,6-dione derivative is a highly nucleophilic substance. Sensitive
It is thought that it cannot exist stably in a reaction system using a nucleophilic substance, but an anion is generated at the 5-position of a 1,3-dioxane-4,6-dione derivative to give 5-methylene- 1,3
To obtain a -dioxane-4,6-dione derivative, one must use a basic substance, and usually a basic substance is at the same time nucleophilic. We have found that these contradictory conditions can be satisfied by using an organic acid as a solvent and an organic acid metal salt as a catalyst, and completed the synthetic method of the present invention.

That is, 1,3-dioxane of the general formula (2)
The hydrogen at the 5-position of the -4,6-dione derivative is hydrogen of a so-called active ester, and an anion is generated even in the presence of a weak base such as an organic acid metal salt, and when an organic acid is used as a solvent, paraformaldehyde is formed. It reacts with and stably forms a 5-methylene-1,3-dioxane-4,6-dione derivative.

Examples of the organic acid used in the synthetic method of the present invention include organic acids such as acetic acid, formic acid and propionic acid, and the preferred organic acid for the present invention is glacial acetic acid. These organic acids are the solvent and 5-methylene formed during the reaction.
It also functions as a stabilizer for the 1,3-dioxane-4,6-dione derivative. As a solvent, an inert solvent such as acetonitrile or dioxane may be mixed and used together with the organic acid. The amount of the organic acid is preferably 1 to 10 times the weight of the 1,3-dioxane-4,6-dione derivative, more preferably 1.5 to 10.
It is three times.

Examples of the organic acid metal salts used in the present invention include metal acetate salts, metal formate salts, and metal salts of propyroic acid, preferably metal acetate salts and metal acetate anhydrides, and more preferably acetic anhydride. sodium,
Examples thereof include anhydrous potassium acetate, anhydrous copper acetate, anhydrous copper acetate, anhydrous barium acetate, anhydrous zinc acetate and the like. Of these, anhydrous copper acetate is particularly preferable. The amount of the organic acid metal salt added is preferably 0.5 to 10% by weight of the reaction solution, and more preferably 1 to 3% by weight. 0.5% by weight
When it is below, the reaction with paraformaldehyde becomes very slow, and when it is 10% by weight or more, the product 5-methylene-1,3-dioxane-4,6-dione derivative is decomposed or the reaction It is preferable to avoid it because it may initiate polymerization inside the liquid.

The molar ratio in the reaction between the 1,3-dioxane-4,6-dione derivative and paraformaldehyde is 1: 1 to 1: 1.
5 is preferable, more preferably 1: 1 to 1: 1.2, and even more preferably 1: 1.2 to 1: 1.5.

The reaction temperature is preferably 30 to 180 ° C, more preferably 80 to 120 ° C, and particularly preferably 90 to 110 ° C. Formaldehyde does not react at temperatures below 30 ° C, and conversely at temperatures above 180 ° C 5-
No methylene-1,3-dioxane-4,6-dione derivative is obtained, only complex decomposition products are obtained.

Unlike the 1,3-dioxane-4,6-dione derivative, the 5-methylene-1,3-dioxane-4,6-dione derivative is not particularly vulnerable to heat, so it can be distilled. Yes, and if liquid, the reaction can be followed by gas chromatography.

By gas chromatography, 5-
When the concentration of the methylene-1,3-dioxane-4,6-dione derivative was traced, it was found that the concentration reached the maximum after a certain period of time, and the concentration decreased when the reaction was continued for a longer time.

The reaction time is preferably 12 to 16 hours when the reaction temperature is 80 ° C., and the reaction temperature is 10
When the temperature is 0 ° C., it is preferably 3 to 4 hours.

The method for adding the 1,3-dioxane-4,6-dione derivative to the reaction system is to add it dropwise after the reaction system has reached 50 ° C. or higher, more preferably 60 ° C. or higher. . If the reaction is carried out by batch charging from the beginning, a large amount of dialkylidene methylene malonate, which is a reaction between 2 molecules of 1,3-dioxane-4,6-dione derivative and 1 molecule of formaldehyde, is generated, and 5-methylene-1, It becomes difficult to obtain a 3-dioxane-4,6-dione derivative.

That is, 5-methylene-1,3-dioxane-4,
It is preferable to set reaction conditions such that one molecule of water is dehydrated immediately after one molecule of 6-dione derivative and one molecule of formaldehyde are reacted, and the catalyst of the present invention, that is, the organic acid metal salt is 1,3-dioxane-4, It is presumed that the 6-dione derivative not only generates an anion but also has a role as a desiccant.

As a method for adding the 1,3-dioxane-4,6-dione derivative which is solid at room temperature to the reaction system, it is preferable to dissolve it in an organic acid and then add dropwise, if it is difficult to dissolve in the organic acid. For example, an inert solvent such as acetonitrile or dioxane can be used.

The resulting 5-methylene-1,3-dioxane-4,6-
The dione derivative has a very high polymerizability and stably exists in the organic acid of the reaction solution, but when it is subjected to an operation such as isolation from the reaction solution or is stored, it is a stabilizer. The present inventors have also found that it is necessary to use an acidic substance as the (polymerization inhibitor), and the derivative can be stabilized by an acidic substance in addition to the reaction in an organic acid to obtain the derivative. That is.

The acidic substance referred to herein is hydrochloric acid, nitric acid, phosphoric acid, zinc chloride, iron chloride, boron trifluoride, sulfur dioxide, paratoluenesulfonic acid, benzenesulfonic acid, acetic acid, formic acid, propionic acid, diphosphorus pentoxide. , Polyphosphoric acid, boron trifluoride, and other strong acids. Preferred for the present invention is diphosphorus pentoxide. Without these acidic substances, polymerization occurs when the 5-methylene-1,3-dioxane-4,6-dione derivative is isolated from the reaction solution, resulting in 5-methylene-1,3-dioxane-4,6- Dione derivatives cannot be obtained. The amount of the acidic substance used as a stabilizer may be about 50 to 1000 ppm in the case of simply storing the derivative, but in the case of isolation or purification from the reaction solution by distillation or the like. The optimum amount must be determined depending on the heating conditions, etc., but generally 5 to 100 parts by weight of the derivative.
It is necessary to use about 10 parts by weight.

Distillation is preferred to isolate the liquid 5-methylene-1,3-dioxane-4,6-dione derivative from the reaction mixture,
It is preferable to charge a high boiling solvent in addition to the acidic substance to the distillation pot. The high boiling point solvent has a role of improving the stirring of the reaction solution. As a high boiling point solvent, it does not have a nucleophilic substituent such as a hydroxyl group or an amino group, and 5-methylene-
It must have a boiling point suitable for separating 1,3-dioxane-4,6-dione derivatives. Preferably di-2-
Phthalates such as ethylhexyl phthalate, dioctyl phthalate, butylbenzyl phthalate, trimellitic esters such as tri-2-ethylhexyl trimellitate, dibutyl sebacate, di-2
-Ethylhexyl sebacate, fatty acid ester compounds such as di-2-ethylhexyl adipate, tricresyl phosphate, tributoxyethyl phosphate, tri
-Orthophosphoric acid ester compounds such as 2-ethylhexyl phosphate, trioleyl phosphate, triphenyl phosphate, trixylenyl phosphate, and "CR-733S, CR-7" from Daihachi Chemical Industry Co., Ltd.
Examples of the aromatic condensed phosphoric acid ester compounds are commercially available under the trade name of "35".

When the distillation is carried out at a particularly high temperature, hydroquinone, hydroquinone monomethyl ether or the like may be added to the distillation pot as a radical polymerization inhibitor.

5-Methylene-1,3-dioxane-solid at room temperature
The 4,6-dione derivative can be isolated by conventional solid-state production methods such as recrystallization and sublimation.

[0041]

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

[0042]

Example 1 5-Methylene-2-methyl-2-ethyl-1,3-dioxane-4,6-di
Synthesis of one ( synthesis of 2-methyl-2-ethyl-1,3-dioxane-4,6-dione) Malonic acid 104.1 g (1 mol), acetic anhydride 122.5
While maintaining a mixture of g (1.2 mol) and concentrated sulfuric acid 7.65 at 25 ° C., 79.3 g (1.1 mol) of methyl ethyl ketone was slowly added dropwise. When the reaction temperature was raised to 30 ° C. after completion of the dropping, malonic acid, which had been in a suspended state until then, was dissolved in a dozen minutes. After stirring for about 12 hours, the reaction solution was cooled to about 10 ° C., and sulfuric acid and unreacted malonic acid were neutralized with an aqueous sodium hydroxide solution and sodium hydrogen carbonate. When extracted with chloroform, washed with water, and evaporated chloroform,
35.2 g of a clear brown viscous liquid (yield 35.2%)
Obtained. From elemental analysis and NMR measurement it was found to be 2-methyl-2-ethyl-1,3-dioxane-4,6-dione. IR (NaCl): 1755, 1786 cm ^-1 (CO) NMR (heavy acetone, δ ppm): 3.82 ppm (dd, 2H, -CH _2- ) 2.02 ppm (q, 2H, -CH _2- ) 1.78 ppm _{(s, 3H, -CH 3)} 1.02ppm (t, 3H, -CH 3) (5- methylene-1,3-dioxane-2-methyl-2-ethyl-4,6
Synthesis of dione) A reactor equipped with a reflux condenser, a stirrer and a thermometer was charged with 1 g (0.03 mol) of paraformaldehyde, 0.4 g of anhydrous copper acetate and 8.84 g of acetic acid and stirred.
The reaction was heated to 60 ° C. 1, when it reaches 60 ℃
3-dioxane-2-methyl-2-ethyl-4,6-dione 3.44 g
(0.02 mol) was slowly added dropwise. After the dropping was completed, the reaction solution was kept at 100 ° C. After 4 hours, the heating was stopped and the temperature was returned to room temperature with stirring. When this reaction solution was left to stand overnight, a small amount of anhydrous copper acetate was precipitated, so it was filtered. 5 in the filtrate
g tricresyl phosphate and 0.5 g diphosphorus pentoxide were added, and the mixture was distilled under reduced pressure to 60 ° C./2 mmHg with stirring to obtain acetic acid and 5-methylene-1,3-dioxane-2-methyl-2-methyl-2-.
The ethyl-4,6-dione mixture was cooled in a dry ice-methanol bath and placed in a receiver charged with 0.02 g of phosphorus pentoxide. To the distilled mixture was added 0.02 g of diphosphorus pentoxide, and a fraction up to 40 ° C / 2 mmHg was taken. The amount of the liquid remaining at that time was 0.5 g, and it was found from NMR measurement that this was 5-methylene-1,3-dioxane-2-methyl-2-ethyl-4,6-dione (yield 14. 7%). When water was dropped onto this product, it instantly changed to a white resinous material. Resinous materials are acetone, chloroform, tetrahydrofuran,
It was insoluble in DMF and DMSO. NMR (heavy acetone, δppm): 7.5ppm (d, 2H, CH ₂ =) 2.02ppm (q, 2H, -CH _2- ) 1.78ppm (s, 3H, -CH ₃ ) 1.02ppm (t 3H, -CH ₃ )

[0043]

Example 2 5-Methylene-2,2-diethyl-1,3-dioxane-4,6-dione
( Synthesis of 2,2-diethyl-1,3-dioxane-4,6-dione) In the same manner as in Example 1, light brown transparent 2,2-diethyl-
35.52 g of 1,3-dioxane-4,6-dione (yield 35.52
%). NMR (heavy acetone, δppm): 3.56ppm (s, 2H, -CH _2- ) 1.80ppm (q, 4H, -CH _2- ) 0.97ppm (t, 3H, -CH ₃ ) (5-methylene Synthesis of -2,2-diethyl-1,3-dioxane-4,6-dione) In the same manner as in Example 1, 5-methylene-2,2
-Diethyl-1,3-dioxane-4,6-dione 0.6 g (yield 1
7.4%). When water was added to this product, it instantly changed to a white resinous material. The resinous material was insoluble in acetone, chloroform, tetrahydrofuran, DMF and DMSO. IR (NaCl): 1753, 1786 cm ^-1 (CO) NMR (heavy acetone, δppm): 7.46 ppm (d, 2H, CH ₂ =) 2.04ppm (q, 4H, -CH _2- ) 1.00ppm ( t, 3H, -CH ₃ )

[0044]

Example 3 5-Methylene-2-methyl-2- (iso-propyl) -1,3-dioxa
Synthesis of benzene-4,6-dione ( synthesis of 2-methyl-2- (n-propyl) -1,3-dioxane-4,6-dione) In the same manner as in Example 1, a brown transparent 2- Methyl-2- (n-propyl) -1,3-dioxane-4,6-dione 47.
3 g (yield 47.3%) was obtained. IR (NaCl): 1755, 1786 cm ^-1 (CO) NMR (heavy acetone, δppm): 3.84ppm (dd, 2H, -CH _2- ) 2.14ppm (m, 1H, -CH-) 1.68ppm ( _{s, 3H, -CH 3) 1.04ppm} (d, 6H, -CH 3) (5- methylene-2-methyl-2- (n-propyl) -1,3-dioxane-4,6-dione ) In the same manner as in Example 1, 5-
Methylene-2-methyl-2- (n-propyl) -1,3-dioxane-4,
0.9 g of 6-dione (yield 24.4%) was obtained. When water was added to this product, it instantly changed to a white resinous material. Resinous materials are acetone, chloroform, tetrahydrofuran,
It was insoluble in DMF and DMSO. NMR (heavy acetone, δppm): 7.12ppm (dd, 2H, CH ₂ =) 2.59ppm (m, 1H, -CH-) 1.80ppm (s, 3H, -CH ₃ ) 1.00ppm (d, 6H, -CH ₃ )

[0045]

Example 4 5-Methylene-2,2-hexamethylene-1,3-dioxane-4,6-
Synthesis of dione ( synthesis of 2,2-hexamethylene-1,3-dioxane-4,6-dione) Malonic acid 104.1 g (1 mol), acetic anhydride 122.5
While maintaining the mixture of g and concentrated sulfuric acid 7.65 at 25 ° C., 108 g (1.1 mol) of cyclohexanone was slowly added dropwise. When the reaction temperature was raised to 30 ° C. after completion of the dropping, malonic acid, which had been in a suspended state until then, was dissolved in about 2 hours, and the reaction solution became dark brown. After stirring for about 12 hours, the reaction solution was cooled to about 10 ° C., and sulfuric acid and unreacted malonic acid were neutralized with an aqueous sodium hydroxide solution and sodium hydrogen carbonate.
A yellow precipitate came out from the middle of the neutralization step. The precipitate was filtered, washed well with water and dried. The residue was dissolved in acetonitrile, the insoluble matter was filtered off, and the acetonitrile was evaporated to obtain 108.67 g (59.0%) of a crude product. Since no particular impurities were confirmed by NMR measurement,
The material was used as it was without recrystallization. IR (KBr): 1763, 1790 cm ^-1 NMR (deuterated chloroform, δ ppm): 3.60 ppm (s, 2H, -CH _2- ) 2.02 ppm (q, 2H, -CH _2- ) 1.78 ppm (s, _{3H, -CH 3) 1.4~2.1ppm (m} , 10H, -CH 2 -) (5- methylene-2,2-hexamethylene-1,3-dioxane-4,6
-Synthesis of dione) A reactor equipped with a reflux condenser, a stirrer and a thermometer was charged with 0.8 g (0.025 mol) of paraformaldehyde, 0.4 g of anhydrous copper acetate and 8 g of acetic acid and stirred. When heating starts and the temperature of the reaction mixture reaches 60 ° C, 2,
2-hexamethylene-1,3-dioxane-4,6-dione 3.7 g
(0.02 mol), 0.5 g of acetonitrile and 8 g of acetic acid were slowly added dropwise. After the dropping was completed, the reaction solution was kept at 100 ° C. After 3 hours, the heating was stopped and the temperature was returned to room temperature with stirring. When this reaction solution was left to stand overnight, a small amount of anhydrous copper acetate was precipitated, so it was filtered. To the filtrate were added 10 g of tricresyl phosphate and 0.5 g of diphosphorus pentoxide, and the mixture was distilled under reduced pressure to 100 ° C / 2 mmHg with stirring to obtain 5% acetic acid.
The mixture of -methylene-1,3-dioxane-2-methyl-2-ethyl-4,6-dione was placed in a receiver charged with 0.05 g of diphosphorus pentoxide cooled in a dry ice-methanol bath. . 0.02 g of diphosphorus pentoxide was added to the distilled mixed solution and the mixture was distilled under reduced pressure to obtain a fraction up to 40 ° C./2 mmHg. There was 0.2 g of liquid remaining at that time, and it was found from NMR measurement that this was 5-methylene-2,2-hexamethylene-1,3-dioxane-4,6-dione (yield 5.1. %). When water was dropped onto this product, it instantly changed to a pale yellow resinous material. The resinous material was insoluble in acetone, chloroform, tetrahydrofuran, DMF and DMSO. NMR (heavy acetone, δppm): 7.02ppm (d, 2H, CH ₂ =) 1.2 to 2.22ppm (m, 10H, -CH _2- )

[0046]

According to the present invention, novel 5-methylene-1,3-
A dioxane-4,6-dione derivative can be obtained, and the compound has high polymerizability and can be applied in various fields including coatings and adhesives.

Claims (3)

[Claims] 1. A 5-methylene-1,3-dioxane-4,6-dione derivative represented by the following general formula (1). Embedded image In the formula, R ₁ and R ₂ are organic groups containing a carbon atom, and although they may be bonded to each other to form a cyclic structure, both are not methyl groups. 2. A method of reacting paraformaldehyde with a 1,3-dioxane-4,6-dione derivative represented by the following general formula (2) in the presence of an organic acid and an organic acid metal salt. Method for synthesizing 5-methylene-1,3-dioxane-4,6-dione derivative. Embedded image In the formula, R ₁ and R ₂ are organic groups containing a carbon atom, and although they may be bonded to each other to form a cyclic structure, both are not methyl groups. 3. A method for stabilizing a 5-methylene-1,3-dioxane-4,6-dione derivative, which comprises stabilizing by adding an acidic substance.