Selective synthesis of vitamin K3 over mesoporous NbSBA-15 catalysts synthesized by an efficient hydrothermal method.
Well hexagonally ordered NbSBA-15 catalysts synthesized by an efficient hydrothermal method were used, for the first time, for the selective synthesis of vitamin K(3) by liquid-phase oxidation of 2-methyl-1-naphthol (2MN1-OH) under various reaction conditions. The recyclable NbSBA-15 catalysts were also reused to find their catalytic activities. To investigate the leaching of non-framework niobium species on the surface of silica networks, the results of original and recyclable NbSBA-15 catalysts were correlated and compared. To find an optimum condition for the selective synthesis of vitamin K(3), the washed NbSBA-15(2.2pH) was extensively used in this reaction with various reaction parameters such as temperature, time and ratios of reactant (2M1N-OH to H(2)O(2)), and the obtained results were also demonstrated. Additionally, the liquid-phase oxidation of 2M1N-OH was carried out with different solvents to find the best solvent with a good catalytic activity. Based on the all catalytic studies, the vitamin K(3) selectivity (97.3%) is higher in NbSBA-15(2.2pH) than that of other NbSBA-15 catalysts, and the NbSBA-15(2.2pH) is found to be a highly active and eco-friendly heterogeneous catalyst for the selective synthesis of vitamin K(3).
School of Chemical and Biomolecular Engineering, Pusan National University, Busan 609-735, Korea. chems@pnu.edu
M
M
Selvaraj
D-W
DW
Park
I
I
Kim
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S
Kawi
C S
CS
Ha
D002384:Catalysis; D009284:Naphthols / Q000737:chemistry*; D009556:Niobium / Q000737:chemistry*; D010084:Oxidation-Reduction; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D013696:Temperature; D024483:Vitamin K 3 / Q000138:chemical synthesis*
D009284:Naphthols; C509969:SBA-15; D009556:Niobium; D024483:Vitamin K 3; D012822:Silicon Dioxide; C569981:2-methyl-1-naphthol