ZHAO Shanshan1, LU Hua2, ZHANG Yuecheng1*, ZHAO Jiquan1
(1. School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130; 2. Hebei Zhongrun Pharmaceutical Cooperation, Limited, CSPC, Shijiazhuang 050041)
Abstract: Two di-pyridylmethyl D(-)-tartaric acid amides 2 and 3 were respectively prepared through the reaction of (-)-diethyl D-tartrate(1) with 2-aminomethyl pyridine and 4- aminomethyl pyridine. The compounds 1, 2 and 3 coordinated with isopropyl titanate, respectively, were used as catalyst in the asymmetric oxidation of the precursor (Eso-I) of esomeprazole with cumene hydroperoxide (CHP) as oxidant. The results revealed that both the catalytic systems derived from ligand 2 and 3 and isopropyl titanate showed good catalytic activity and enantioselectivity in the synthesis of esomeprazole. For example, the conversion of Eso-I, the selectivity toward to the esomeprazole and the enantio excess reached 84.7%, 91.8% and 89.0%, respectively, when 2 was used as the ligand and the reaction was conducted in toluene under the optimized conditions.
Key words: D(-)-Di-pyridylmethyl tartaric acid amide; sulfide; asymmetric oxidation; esomeprazol
E-mail: zyctju@yahoo.com.cn
Journal of Molecular Catalysis, Vol. 26, Issue 1, 2012, 46-51
