Use of 1-methyl-4-isopropyl-bicyclo[2,2,2] octane-2,3-dicarboxylic acid

[0014] Example 1 (Preparation of 1-methyl-4-isopropyl-bicyclo[2,2,2]octene-2,3-dianhydride)

[0015] In a four-necked flask equipped with a thermometer, dropping funnel, mechanical stirrer, and condenser, add maleic anhydride (2.5 times the mole based on α-terpinene) and heat to dissolve maleic anhydride, and control it to 65 At -70℃, add the terpinene mixture (α-terpinene oil content 32.4%, γ-terpinene 15.6%, iso-terpinene 14.6%, iso-terpinene 6.9%, Dipentene 5.1%, camphene 4.5%, β-pinene 3.5%, α-pinene 3.4%, p-Meng-3,8-diene 1.9%). After dripping, react at 135-140℃, distill to remove low-boiling components to obtain the crude product, and collect the fraction under 160-170℃ / 3mmHg by vacuum distillation to obtain the product 1-methyl-4-isopropyl-bicyclo[ 2,2,2]octene-2,3-dianhydride, the structure was confirmed by infrared spectroscopy and nuclear magnetic resonance.

[0016] Example 2 (hydrogenation reaction)

[0017] After dissolving 20 g of 1-methyl-4-isopropyl-bicyclo[2,2,2]octene-2,3-dioic anhydride, the distillation product synthesized in Example 1, in 50ml of methanol, the methanol solution Placed in the autoclave, and then weighed 1.0 g of Raney nickel catalyst (Raney NiW2), washed with methanol to neutrality, and added to the reactor. After replacing the air in the kettle with hydrogen, the hydrogen was filled to 3MPa, and the stirrer was turned on at 100°C and the stirring speed was adjusted to 500 rpm. The reaction started, the reactants began to absorb hydrogen, and the hydrogen pressure dropped. When the hydrogen pressure drops to 0.1 MPa, add hydrogen to 3 MPa, repeat this operation, and the reaction is complete after 40 hours. After removing the catalyst under reduced pressure with a filter aid, use a rotary evaporator to evaporate the solvent to obtain a crude hydrogenated product, and recrystallize with 2 times the amount of n-hexa

[0018] Example 3 (hydrolysis reaction)

[0019] The hydrogenation product 1-methyl-4-isopropyl-bicyclo[2,2,2]octane-2,3-dianhydride obtained in Example 2 was slowly added to an excess of 6M sodium hydroxide aqueous solution Stir and extract twice with methyl chloride to remove insoluble materials. The aqueous layer was neutralized with 3N sulfuric acid aqueous solution, crystals were precipitated, and white crystals were filtered under reduced pressure to obtain 1-methyl-4-isopropyl-bicyclo[ 2,2,2]octane-2,3-dicarboxylic acid, mp 133.5-134.8°C, the structure was determined by infrared spectroscopy and nuclear magnetic resonance, used as solder A for soldering test.