JPS5919949B2 - Naphthalene derivatives and their production method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel naphthalene derivative and a method for producing the same.

The naphthalene derivative according to the present invention is represented by the following general formula and is useful as a curing agent for polyester resins, epoxy adhesives and paints, detergent bilters, radical scavengers, photographic materials, redox agents, and the like.

(In the formula, R represents a lower alkyl group) The compound 1) according to the present invention has an unsaturated double bond in the side chain represented by the general formula (In the formula, R represents the same meaning as above) Dissolve the phenolic compound and maleic anhydride in an inert organic solvent,
Produced at room temperature or by heating.

In this case no catalyst is required. The raw material compound (2) used in the present invention is already known, for example, as described in British Patent No. 905994,
It is produced by thermally decomposing parahydroxydiphenylalkane corresponding to the compound of formula (2). Alternatively, Journal of Orcanic Chemistry 1,
According to Vol. 23, p. 544 (1958), it is produced by dehydrogenating the alkylphenol of the compound represented by formula (2). The compound represented by the above (supporting) formula includes a parkyl group, phenyl group, and hydroxyl group, and since these are all electron-donating groups, the electron density of the unsaturated double bond is extremely high.

On the other hand, maleic anhydride has electron-withdrawing carbonyl groups bonded to both ends of an unsaturated double bond, so the electron density at the double bond position is extremely low. In this way, when two compounds with completely opposite electron densities at the double bond positions are mixed, electrons move from the side with higher electron density at the double bond position to the side with lower electron density without using any catalyst, resulting in charge transfer. Forms a complex. J From the reaction between the compound of formula 2) and maleic anhydride, (1
Although the reaction that produces the compound () is classified as a Diels-Alder reaction, the charge transfer complex as an intermediate is thought to play an important role in promoting the reaction.

Although the formation of a charge transfer complex can be confirmed with the naked eye as it turns yellow when both raw materials are mixed,
Using the ultraviolet absorption spectrum, the continuous change method [W. C. O
sburgh. G. R. COOperl Journal of American Chemical Society Vol. 63, p. 437 (1961)]. According to the results of applying this method, the composition of the complex is that both raw materials are 1:1.
It was composed of a molar ratio of Further, the amount of charge transfer complex produced is inversely proportional to the temperature of the mixed system and proportional to the square of the concentration. Therefore, in order to efficiently synthesize the compound shown by formula (1), the phenol compound shown by the &Kanibi formula and maleic anhydride are mixed at a molar ratio as close to 1:1 as possible, and the concentration of the reaction system is increased as much as possible. It is important to keep the reaction temperature low and to conduct the reaction under conditions that allow the formation of many charge transfer complexes. However, since the reaction between both raw materials is a Dales-Alder reaction, it is better to heat the reaction to increase the reaction rate, so the reaction temperature and reaction solvent also need to be carefully considered and adjusted. The inert solvent used in the present invention is a solvent that does not react with both the raw materials of the phenol compound and maleic anhydride shown in formula (2) and does not form a charge transfer complex. Moreover, it refers to a solvent that has high solubility for both raw materials, and solvents such as water, alcohols, dimethylformamide, dimethyl sulfoxide, hexamethylphosphotriamide, and aromatic hydrocarbons may react with maleic anhydride or cause charge transfer. It is unsuitable because it forms an acid form. On the other hand, if the reaction temperature is too high, the number of complexes decreases while a large amount of high molecular weight substances are produced, which is not preferable. Generates alkylation catalysts such as Lewis acids and radicals as reaction catalysts. Even when a catalyst is used, it becomes a high molecular weight alternating copolymer (1)
The compound shown in the formula is not obtained. Specific examples of the compounds shown in (4) 2) used in the present invention include P-isopropenylphenol, 2-(P-hydroxy.diphenyl)-1
-butene, 2-(P-hydroxyphenyl)-1-benzene, 2-(P-hydroxyphenyl)-3-methyl-
Examples include 1-butene, 2-(P-hydroxyphenyl)-1-hexene, and 2-(P-hydroxyphenyl)-4-methyl-1-benzene. The mixing ratio of the raw materials to be reacted is not particularly limited, but since the product is a 1:1 molar adduct, it is preferable to mix them at a 1:1 molar ratio, and adding a large amount of maleic anhydride increases the molecular weight. do. The solvent used in the present invention needs to be an inert solvent that can dissolve both the phenolic compound and maleic anhydride well, and, importantly, does not react with them or form complexes with them, preferably dioxane, Preferred examples include tetrahydrofuran, acetone, methyl ethyl ketone, ethyl ether, propyl ether, and ethyl acetate. When dissolving both raw materials in these organic solvents, it is better to dissolve them at as high a concentration as possible, and generally the saturated concentration is 5 mol/l, calculated based on the total number of moles of both raw material compounds. The concentration may be about 2 mol/l, but preferably 3 mol/l.
．． 5 mol/l to 5 mol/l is preferable.

The organic solvent used in the reaction is one that has been sufficiently dehydrated and purified using a dehydrating agent. In order to avoid oxidation reactions, it is better to replace the air in the reaction system with nitrogen. Next, in a preferred embodiment of the present invention, the phenol compound or maleic anhydride represented by formula (1) is weighed into a reaction tube with a screw cap, completely dissolved in the solvent, and then the same number of moles as the above solvent is added. Add the other compound and mix and dissolve.

At this time, the colorless solution turns yellow. The air at the top of the reaction tube is replaced with nitrogen by blowing nitrogen to avoid oxidation, and then the screw cap is closed. Next, the reaction tube is placed in a constant temperature bath at room temperature to 50°C and reacted. The reaction time depends on the reaction temperature; at room temperature, the reaction time is 7
5 days if the temperature is 30℃, 3 days if the temperature is 40℃,
When the temperature is 50°C, the reaction is allowed to take place for about 2 days. In many cases, a white precipitate of the desired product is produced during the reaction. Next, remove the reaction tube from the thermostat, cool it to room temperature, open the lid,
If necessary, the pressure is reduced to such an extent that the charged raw materials do not precipitate, the solvent is evaporated and concentrated, and the reaction is repeated at a temperature of room temperature to 50°C by the same procedure as the beginning. A white precipitate of the target product gradually increases in the reaction tube. After performing this operation 2 to 3 times, the white precipitate is passed through the mouth, and the mouth liquid is poured into a large amount of ethyl ether-benzene mixture to obtain further white precipitate, which is passed through the mouth and obtained first. Combined with the precipitate,
Wash thoroughly with ethyl ether-benzene mixture or soak overnight in this solution. Pass through the mouth again and vacuum dry at room temperature for 24 hours. This white crystal is the compound shown in (1). Unreacted raw materials are dissolved in the ether-benzene mixture and have already been removed. The compound represented by formula (1) has a lower solubility in ordinary organic solvents than the respective raw materials or polymerized compounds, so it can be easily separated from unreacted substances and reaction by-products. Although the elucidation of the reaction mechanism is not fully clear, it is still possible that a Deels-Alda reaction occurs between the α-position double bond of the phenol compound shown in formula (2), the double bond of the benzene ring, and the double bond of maleic anhydride. ,
It is thought that a cyclic adduct is formed, and then, since the hydroxyl group of the phenol group present at the double bond position is unstable, a reaction proceeds in which hydrogen is eliminated and rearranged to form a stable α/β unsaturated ketone.

This reaction may be carried out continuously.

In this case, the reaction time is defined as the residence time in the system. Next, the present invention will be explained in more detail with reference to Examples.

Example 1 5.37 f (0.04 mol) of P-isopropenylphenol was weighed into a glass reaction tube with a screw cap and an internal volume of 30 m1.
Add 20ml of tetrahydrofuran and dissolve completely.

To this was added 3.92 (0) maleic anhydride weighed in advance.
．． 04 mol) and mix well to dissolve. After blowing nitrogen gas into the top of the reaction tube to replace the air with nitrogen, the tube was quickly capped with a screw cap, fixed in a constant temperature bath at 40° C., and allowed to react for 3 days with occasional shaking. A white precipitate is produced during the reaction process, but the reaction is continued, and on the third day, the precipitate is passed through the mouth, and the oral liquid is concentrated under reduced pressure to about two-thirds of the total volume, and then the same as before. The operation is repeated two more times, and after the third reaction, the contents of the tube are poured into 50 d of benzene-ethyl ether mixed solution and stirred well. At this time, the desired reaction product becomes a white powder and precipitates. The precipitate is passed through the mouth, combined with the previously obtained precipitate, and soaked overnight in a benzene-ethyl ether mixed solution. Take this in your mouth and leave it at room temperature for 2
Vacuum dry for 4 hours. The reactant was 8.08f and the yield was 87
It was %. This product is insoluble in benzene, toluene, carbon tetrachloride, n-hexane, etc., which have low polarity, and slightly soluble in acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, dimethylformamide, etc., and soluble in alcohols and alkaline aqueous solutions. The melting point of the product is 195-196°C, and according to infrared absorption vector analysis it is 1645°C. Absorption of α/β unsaturated ketones is seen at -1, and absorption of acid anhydrides is 1770? -1 and 1840 (177
! -1 due to the benzene ring (1-J mo V!
-1 absorption is not observed at all. The results of nuclear magnetic resonance spectra show that the unsaturated methine protons due to the formation of d/β-unsaturated ketones are located at completely different positions from the P-substituted benzene nuclear protons at 7.5017.36, 5.82, and 5.68p.
pm, and methyl group proton absorption appears at 1.89 ppm.

Comparing these area integral values, 7.50, 7.36
The sum of the areas of ppm and the sum of the areas of 5.82 and 5.68 ppm are equal, and the area value of 1.89 ppm is three times the former. Therefore, the unsaturated methine proton belongs to the α/β monounsaturated ketone, and R in the compound shown in formula (1) is represented by a methyl group. Anhydrous-1-methyl-2.3.
4,4a,5-pentahythro-6-oxonaphthalene-4,5-dicarboxylic acid.

The acid anhydride of this compound is ring-opened and dissolved in a 5% alkaline aqueous solution. When this alkaline solution is neutralized with acid, sodium carboxylate turns into carboxylic acid and precipitates. Further, when dissolved in methyl alcohol and refluxed for 3 hours, the acid anhydride is ring-opened, and one becomes a methyl ester and the other becomes a carboxylic acid, yielding a half-methyl ester compound with a melting point of 134°C. Example 2 In a 50 WLI reaction tube with a screw cap, 4.7y (0.035 mol) of P-isopropenylphenol is dissolved in 20 ml of acetone.

Claims (1)

[Claims] 1. A naphthalene derivative represented by the general formula ▲There are numerical formulas, chemical formulas, tables, etc.▼ (in the formula, R represents a lower alkyl group). 2 A phenol compound represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R represents a lower alkyl group) and maleic anhydride are dissolved in an inert organic solvent and reacted at room temperature or by heating. A method for producing a naphthalene derivative represented by the general formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (in the formula, R represents the same meaning as above). 3. The method according to claim 2, wherein the heating reaction temperature is from room temperature (around 20°C) to 50°C. 4. The method according to claim 2 or 3, wherein the mixing ratio when the phenol compound and maleic anhydride are dissolved in an inert organic solvent is close to 1:1. 5 The amount of phenolic compound and maleic anhydride when dissolved in an inert organic solvent is at least 2 mol/mole/mole/mole in total concentration.
1. The method of claim 2, claim 3, or claim 4, wherein: l. 6. The method according to claim 2, 3, 4, or 5, wherein the inert organic solvent is at least one selected from ethers, ketones, and esters, or a mixture thereof.