Oxygen → 3,5-Dihydroxy-1-adamantyl methacrylate

참여 물질

반응 단계

To a 2 L jacket-equipped separable flask provided with a stirrer, a thermometer, a Dean-Stark water separator, a Dimroth condenser and a prepared gas introduction tube, 128.9 g of 1,3,5-adamantanetriol, 361 g of methacrylic acid, 1.7 g of concentrated sulfuric acid as an acid catalyst, 1.1 g of p-methoxyphenol as a polymerization inhibitor, and 750 ml of toluene as a solvent were put. Prepared gas diluted with nitrogen so as to have an oxygen concentration of about 5% by volume was supplied at a rate of 0.2 L/min. The reaction operation was performed as follows. While the solution was heated and water generated as a secondary product was removed by the Dean-Stark water separator, the reflux state was continued for 12 hours. Thus, 3,5-dihydroxy-1-adamantyl methacrylate was synthesized. The obtained reaction solution was cooled down to room temperature, and then a 10% by weight of aqueous solution of sodium hydroxide was added while stirring to neutralize the residual methacrylic acid and sulfuric acid. Then, the neutralized water phase was drawn out from the two-phase solution. The resultant organic phase was washed with 500 ml of ion exchange water twice. After the water phase was all united, extraction was performed with 300 ml of ethyl acetate twice. To the ethyl acetate solution, 0.76 g of p-methoxyphenol was added as a polymerization inhibitor and dissolved completely. Precise filtration was performed by use of a Teflon® filter having a pore diameter of 0.1 μm. Then, the resultant solution was concentrated by use of an evaporator while the temperature of the solution was kept at 40° C., until the weight of the solution became 110 g. After the concentration was finished, cooling crystallization was performed at a temperature of an ice water bath to separate the crystal by filtration. The crystal was rinsed with ion exchange water twice, and then dried at a reduced pressure at 35° C. for 24 hours. During the process from the dehydration esterification reaction to the solid-liquid separation and until the termination of rinsing performed by use of ion exchange water, the prepared gas was kept blown into the solution. Table 1 shows the analysis results of the obtained 3,5-dihydroxy-1-adamantyl methacrylate. Tetrahydrofuran was used as the solvent for measuring the turbidity.

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