JPH0460100B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is represented by the structural formula [] tricyclo[5.2.1.0 ^2.6 ]dec-3-ene-8,
This invention relates to a 9-dicarboxylic acid diester (R represents alkyl, unsaturated alkyl, or cycloalkyl) and a method for producing the same. The compound of the present invention is a new compound, and this type of dicarboxylic acid is generally used in the field of resins, typified by epoxy thermosetting agents, polyester resins, etc.
Its applications are extremely wide-ranging, including agricultural chemicals such as antibacterial agents and herbicides, as well as precursors for pharmaceuticals such as central nervous system and circulatory agents. Particularly in the field of resins, it is expected to be used as a raw material or intermediate for paints, adhesives, PVC plasticizers, etc., which have characteristics such as heat resistance, electrical properties, and solubility in solvents.
The present inventors have also filed a patent application (Japanese Patent Application No. 114934/1982) regarding polyimide. The compound of the present invention can be produced by two routes represented by the following formula. (1) tricyclo[5.2.1.0 ^2.6 ]dec-3-ene-
8,9-dicarboxylic acid diester (abbreviation)
TCDE) (2) Recyclo [5.2.1.0 ^2.6 ] dec-3-ene-8,
9-Dicarboxylic acid (abbreviated as TCDE) (R': represents an alkyl, unsaturated alkyl, or cycloalkyl group different from R.) Namely, (1) Direct diesterification of dicyclopentadiene. (2) Obtained by diesterization
This is a method to obtain TCDE by hydrolyzing TCDE to TCDC and then esterifying it with an alcohol different from the alcohol used for diesterization. Hereinafter, the first method for diesterifying dicyclopentadiene will be explained first. Conventionally, an example of direct diesterization of cycloolefins is that of J.K. Stille.
et al., in the Journal of the American Chemical Society (J.Am, Chem, Soc.), Vol. 98, No. 7, p. 1810 (1976), have only discussed cyclomonoolefins, and the number of studies is extremely small. The present inventors have conducted intensive studies on a method for selectively directly diesterizing one double bond of dicyclopentadiene, which is one of the cyclodiolefins, and surprisingly found that norbornene The present invention was completed by discovering a reaction in which only the double bond of the cyclopentene ring is selectively diesterized in high yield while the double bond of the ring remains. Dicyclopentanediene, which is the raw material of the present invention, is contained in a considerable proportion in the _C5 fraction obtained by cracking naphtha, and as there is currently a large surplus, the industrial significance of its effective utilization is extremely high. You can say it's big. First, the diesterification of the present invention is basically made possible by the oxidative addition reaction of Pd ²⁺ , and palladium is generally used as a catalyst, but the diesterification can also be carried out even in the absence of palladium. It was also found that the reaction progressed.
Palladium can be used in any form, including inorganic acid salts, organic acid salts, supported palladium, and colloidal metals. Specifically, palladium chloride, palladium nitrate, palladium sulfate, palladium acetate, palladium propionate, palladium-carbon, palladium-silica,
Examples include palladium-alumina, palladium-barium carbonate, palladium black, and colloidal palladium. If the amount used is 0.1 mol % or more based on the raw material dicyclopentadiene, a high yield of diester can be obtained. Furthermore, since Pd ²⁺ is reduced to Pd ⁰ by the reaction, an oxidizing agent is required to return this to Pd ²⁺ . As the oxidizing agent, a metal compound with a low redox potential is preferable, and in particular, a copper or iron compound is used. Specifically, cupric chloride, cupric nitrate, cupric sulfate, cupric formate, cupric acetate, ferric chloride, ferric nitrate, ferric sulfate, ferric formate, Ferric acetate and the like are used, especially copper compounds giving excellent results. In addition, when these compounds are anhydrous, the diester can be obtained in a higher yield, whereas when they are hydrated, the yield tends to be lower. The amount of these oxidizing agents to be used is a theoretical amount based on the raw material, and when a so-called catalytic amount of palladium catalyst is used in the diesterification reaction of the present invention, it is necessary to use 2 times the mole of the raw material dicyclopentadiene. On the other hand, it is also possible to use molecular oxygen as the oxidizing agent without using a metal compound, and a combination of a metal compound and molecular oxygen can also be used. When using molecular oxygen as the oxidizing agent, it is important to add a dehydrating agent such as oil methyl formate, methyl orthoacetate, ethyl orthoformate, or 1,1-dimethoxycyclohexane, which is also an alcohol derivative. A remarkable improvement in yield is observed. Moreover, in the present invention, it was surprisingly discovered that even a metal compound as an oxidizing agent alone causes an oxidative addition reaction and a diesterification reaction proceeds. Under these conditions, the reaction rate is lower than when a palladium catalyst and a metal compound are used in combination, but the selectivity for the desired diester is high. Therefore, industrially, this may be an effective condition for reducing catalyst costs. Alcohol, which is another raw material for diesterification, includes alkyl alcohol, unsaturated alkyl alcohol, cycloalkyl alcohol, benzene-substituted alkyl alcohol,
In the benzene-substituted unsaturated alcohol, the alkyl and unsaturated alkyl may contain O and N atoms.
It does not matter whether the alcohol is alcoholic or polyhydric. Specifically, methanol, ethanol, butanol, nonanol, tridecanol, cyclohexanol, benzyl alcohol, allyl alcohol, cinnamyl alcohol, furfuryl alcohol, propargyl alcohol, geraniol, nerol, ethylene glycol, propanediol, glycerin, ethanolamine, Examples include propanolamine. The alcohol can also be used in the form of its derivatives such as acetals, ketals, and alkyl orthoformates, and the reaction proceeds in the same manner. For example, when using methyl orthoformate, methyl orthoacetate, 1,1-dimethoxycyclohexane, etc., dimethyl ester can be obtained in the same way as when using methanol. Furthermore, as a solvent, pentane, n-hexane,
Hydrocarbons such as cyclohexane and heptane can be used, but alcohol, which is one of the raw materials, or its derivatives such as acetal, ketal, alkyl orthoformate, etc. can be added to dicyclopentadiene in an amount greater than the theoretical amount and used as a solvent as it is. You can also do it. Furthermore, water, acetic acid, N,N-dimethylformamide (DMF), etc. are not preferred as solvents because they reduce the diester yield. The amount of solvent is not particularly limited, but is preferably about 0.1 to 3 times the weight of dicyclopentadiene. Furthermore, a base may be present to remove by-product acids from the catalyst and oxidizing agent during the reaction, thereby suppressing by-products such as halides. Preferred bases include fatty acid salts such as sodium acetate, sodium propionate, and sodium butyrate. Regarding the reaction temperature, the reaction proceeds sufficiently at around room temperature, but it can also be carried out at 100°C or higher. The pressure of carbon monoxide is not particularly limited, but is preferably normal pressure to 50 kg/cm ² G. In the case of low pressure, the reaction time becomes longer and the diester selectivity tends to decrease. Carbon monoxide does not need to be highly pure, and oxo gas, which is a mixed gas with hydrogen, can be used in the same way as carbon monoxide, and is industrially advantageous. The reaction time is correlated with the amount of catalyst, carbon monoxide pressure, etc., but it can usually be completed in about 15 minutes to 2 hours, and when the reaction time is longer, the diester yield generally decreases. Next, a second method will be described in which the diester thus obtained is hydrolyzed and re-esterified. First, hydrolysis can be carried out by using acids such as hydrochloric acid or sulfuric acid, or by using bases such as aqueous sodium hydroxide or potassium hydroxide, but in particular, by using a base, it can be easily and quantitatively The reaction progresses and tricyclo[5.2.1.0 ^2.6 ] dece-
A dialkyl 3-ene-8,9-dicarboxylic acid salt is obtained. Hydrolysis with a base can be easily completed by dissolving the starting diester in an alcohol solvent such as ethanol or propanol, adding a slightly excess aqueous alkaline solution to the theoretical amount, and stirring for 1 to 2 hours at around the reflux temperature of the alcohol. TCDC is obtained by treating the alkali salt thus obtained with an acid such as hydrochloric acid or sulfuric acid. This TCDC is obtained as white crystals by recrystallization and purification using acetonitrile or the like as a solvent. Next, an excess amount of alcohol and 1 to 2 drops of concentrated sulfuric acid are added to this TCDC, and esterification is carried out while heating and dehydrating under reduced pressure. After the reaction, excess alcohol is distilled off under reduced pressure to obtain the desired ester. Examples of the alcohol used in this second method include alkyl alcohol, unsaturated alkyl alcohol, and cycloalkyl alcohol. EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto. Example 1 (dimethyl ester) In a Hastelloy autoclave with an internal volume of 100 ml,
Dicyclopentadiene (DCPD) 3.95g
(30mmol), palladium chloride 0.267g (1.5mmol),
Anhydrous cupric chloride (95% purity) 10.4g (73mmol),
Prepare 24g of methanol and generate 35Kg/cm ² of carbon monoxide.
After pressurizing to G, the reaction was started at room temperature (25°C). Carbon monoxide absorption started immediately and 15 minutes later, the pressure reached 5 kg/cm ² G and absorption stopped. The reaction was exothermic and reached a maximum temperature of 48°C. After stirring for an additional 15 minutes, the reaction was stopped, the autoclave was returned to room temperature, carbon monoxide was removed, and the reaction solution was taken out. After removing the solvent from the reaction solution by concentrating it as it was, the reaction product was extracted with n-hexane. As a result of gas chromatography analysis of this n-hexane solution, no dicyclopentadiene as a raw material remained and an almost single peak was detected as a product. Therefore, this reaction was repeated 5 times in exactly the same way, and after concentrating the reaction solution, the 5 times of n-hexane extracts were combined and concentrated, and further distilled under reduced pressure to 140 to 145
33 g of a fraction of °C/0.7 mmHg was obtained. The analysis results of this distillate were as follows. IR (NaCl): 2930, 1730, 1430, 1200 (cm ^-1 ) ¹³ C-NMR (CDCl ₂ ): 174.1, 173.9, 131.9,
131.5, 52.5, 51.5, 46.4, 44.3, 43.3, 43.1,
41.8, 38.7, 32.2 (δPPM) Mass spectrum (m/e (%)): 250M ⁺ , 25) 218
(100), 124 (63), 66 (80) Elemental analysis: as C ₁₄ H ₁₈ O ₄

[Table] Shown by the structural formula []. From the above, it was found that this fraction was tricyclo[5.2.1.0 ^2.6 ]dec-3-ene-8,9-dicarboxylic acid diester (abbreviated as dimethyl ester). Furthermore, as a result of quantifying the n-hexane solution by gas chromatography, the reaction yield of dimethyl ester was 98%. Examples 2 and 3 (Dimethyl ester) Table 1 shows the results of the reaction conducted in the same manner as in Example 1 except that part or all of the methanol was changed to methyl orthoformate.

[Table] Examples 4 to 11 (dimethyl ester) Table 2 shows the results of the same reaction as in Example 1 except that the type of catalyst and oxidizing agent, the molar ratio of catalyst and oxidizing agent, and the reaction time were changed. .

[Table] Examples 12 to 14 (Dimethyl ester) Part or all of the anhydrous cupric chloride in Example 1 was exposed to molecular oxygen (oxygen pressure 20 Kg/cm ² G, therefore reaction pressure 55 Kg/cm ² G). Example 1 was carried out in the same manner as in Example 1, except that the ratio of alcohol and dehydrating agent was changed, and the results are shown in Table 3.

[Table] Examples 15 and 16 (dimethyl ester) Table 4 shows the results of a reaction conducted in the same manner as in Example 1 except that the carbon monoxide pressure was changed.

[Table] Examples 17 to 20 (dimethyl ester) Table 5 shows the results of a reaction conducted in the same manner as in Example 1 except that a palladium-supported catalyst was used as the catalyst and the oxidizing agent, temperature, and time were changed.

[Table] Example 21 (Dimethyl ester) Into a glass four-necked flask, 212 g (1.6 mol) of dicyclopentadiene (DCPD), 4.0 g (0.023 mol) palladium chloride, and anhydrous cupric chloride (purity 95
%) 465g (3.5mol) and 800g of methanol were heated to 50°C, then carbon monoxide was added to the mixture under normal pressure.
Bubbling was carried out for 2 hours while stirring at a flow rate of 1 min. After the reaction, the reaction product was cooled and the solvent was removed, followed by extraction with n-hexane. After concentrating this hexane solution, it was distilled under reduced pressure to a temperature of 135 to 143℃/
284g dimethyl ester (98% purity) at 0.5mmHg
I got it. Example 22 (Di-n-butyl ester) The reaction was carried out in the same manner as in Example 1 except that methyl alcohol was replaced with n-butanol and the reaction time was changed to 1.8 hours. After removing the solvent from the reaction solution by concentrating it as it was, the reaction product was extracted with n-hexane. As a result of analyzing this n-hexane solution by gas chromatography, it was found that no raw material dicyclopentadiene remained and 82% of the main product was produced. This main product was separated and purified by column chromatography (silica gel Wakogel (C-200)), and the results of further analysis were as follows. IR (NaCl): 2900, 1720, 1180 (cm ^-1 ) Mass spectrum (m/e (%)): 334 (20), 261
(80) 205 (100), 66 (85) Elemental analysis: as C ₁₉ H ₂₆ O ₄

[Table] From the above, this main product is tricyclo[5.2.1.0 ^2.6 ]dec-3-ene-
It turned out to be 8,9-dicarboxylic acid di-n-butyl ester. Example 23 (Di-n-decyl ester) Two drops of concentrated sulfuric acid were added to 3 g of TCDC and 20 g of n-decyl alcohol, and the mixture was allowed to react under reduced pressure while being dehydrated in a bath at 180° C. for 2 hours. Analysis of the reaction solution by gas chromatography revealed that there was only a small amount of unreacted TCDC, and a single product peak appeared. After distilling off excess n-decyl alcohol under reduced pressure, the reaction solution was subjected to column chromatography (silica gel Wako gel (C
-200)) to separate and purify the product. The analysis results were as follows. IR (Nal): 2900, 1720, 1180 (cm ^-1 ) Mass spectrum (m/e (%)): 502(4), 397(8),
345 (22), 205 (100), 137 (14) Elemental analysis: as C ₃₂ H ₅₄ O ₄

[Table] From the above, this main product is tricyclo[5.2.1.0 ^2.6 ]dec-3-ene-
It turned out to be 8,9-dicarboxylic acid di-n-decyl ester. Example 24 (Diallyl ester) The reaction was carried out in the same manner as in Example 1 except that allyl alcohol was used instead of alcohol. Further, as a result of the same post-treatment and analysis, it was found that 64% of the main product was produced. This main product was analyzed by column chromatography (silica gel Wakogel (C-
The results of further analysis were as follows. IR (NaCl): 2900, 1720, 1180 (cm ^-1 ) Mass spectrum (m/e (%)): 302 (5), 245 (59)
，
203 (100), 98 (57) Elemental analysis: as C ₁₈ H ₂₂ O ₄

[Table] From the above, this main product is tricyclo[5.2.1.0 ^2.6 ]dec-3-ene-8,
It turned out to be 9-dicarboxylic acid diallyl ester. Example 25 (Dicyclohexyl ester) The reaction was carried out in the same manner as in Example 1 except that the alcohol was replaced with cyclohexanol and the reaction time was changed to 4 hours. Further, the post-treatment was carried out in the same manner, and as a result of analysis, it was found that 61% of the main product was produced. This main product was separated by column chromatography (silica gel Wakogel (C-200)), and the results of further analysis were as follows. IR (NaCl): 2900, 1720, 1180 (cm ^-1 ) Mass spectrum (m/e (%)): 386(1), 305(8),
205(100), 67(19) Elemental analysis: as C ₂₄ H ₃₄ O ₄

[Table] From the above, this main product is tricyclo[5.2.1.0 ^2.6 ]dec-3-ene-
It turned out to be 8,9-dicarboxylic acid dicyclohexyl ester. Examples 26 to 27 (Various diesters) Table 6 shows the results of reactions conducted in the same manner as in Example 1, except that the alcohol type, temperature, and time were changed.

【table】

Claims (1)

[Claims] 1 Represented by the structural formula [] tricyclo[5.2.1.0 ^2.6 ]dec-3-ene-8,
9-dicarboxylic acid diester (R represents alkyl, unsaturated alkyl, or cycloalkyl). 2 Using dicyclopentadiene, carbon monoxide, alcohol and/or alkyl orthoformate as raw materials,
Structural formula characterized by reaction under a palladium catalyst using one or more oxidizing agents selected from inorganic acid salts and/or organic acid salts of copper and/or organic acid salts of iron [] A method for producing tricyclo[5.2.1.0 ^2.6 ]dec-3-ene-8,9-dicarboxylic acid diester represented by: