In this paper, the catalysts of zirconium oxychloride on molecular sieve were prepared by immersion, and which was employed to catalyze the condensation reaction of 4-cyanopyridine and ethanol amine for synthesizing the pharmaceutical intermediates of 2-(pyridin-4-yl)-4,5-dihydrooxazole under solvent-free conditions. The resultants were identified by gas chromatography - mass spectrometry and the contents were determined by gas chromatography. The results indicated that, These catalysts all exhibit high catalytic activity. The activity is mainly derived from ZrOCl2·8H2O. It is also affected by the specific surface area of the carrier and the number of acidic sites. ZZrOCl2·8H2O/H-MCM-41 has the highest activity. By single factor multi-levels experiments, the optimal technology for the synthesis of 2-(pyridin-4-yl)-4,5-dihydrooxazole was obtained. The optimal conditions were as follow: the molar rate of 4-cyanopyridine to ethanol amine was 1:2, 10% ZrOCl2·8H2O/H-MCM-41 was used as catalyst, catalyst dosage was 10% mass of reactants, reacted at 110 ℃ for 3 h. Under the optimum technology, the conversion of 3-cyanopyridine was up to 98.4%.
李鑫, 邱俊. 2-(4-吡啶基)-4,5-二氢恶唑的催化合成 [J]. 兴发pt登录学报, 2019, 36(9): 18-21. LI Xin, QIU Jun. Catalytic Synthesis of 2-(pyridin-4-yl)-4,5-dihydrooxazole. Journal of Jilin Institute of Chemical Technology, 2019, 36(9): 18-21.