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AssigneeKabushikikaisha Kojundokagaku Kenkyusho
InventorsHidekimi Kadokura, Masamichi Matsumoto, Tadashi Ishii, Yumie Okuhara, Yoshinori Kuboshima, Hiroshi Matsumoto
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The invention provides true La(OiPr)3 preferable as a starting material for an asymmetric synthesis catalyst and a process for producing the same. In this process, anhydrous lanthanum chloride LaCl3 is reacted with potassium isopropoxide K(OiPr) in a mixed solvent of isopropanol and toluene, then the isopropanol is distilled away to replace all the solvent by toluene, then the reaction solution is left, decanted and filtered to give a transparent filtrate, and the solvent is distilled away from the filtrate which is then vacuum-dried under heating, whereby high-purity La(OiPr)3 is obtained in 77% yield. In this high-purity La(OiPr)3, the La content is 97 to 103% of the theoretical content, impurity K is 0.3% or less, (Li+Na) is 0.01% or less, Cl is 0.2% or less, and the degree of association thereof is 5.5 to 6.5.
A process for producing high-purity lanthanum isopropoxide, which comprises reacting anhydrous lanthanum chloride LaCl3 with potassium isopropoxide K(OiPr) in a mixed solvent of isopropanol and toluene, then distilling the isopropanol away to replace all the solvent by the toluene, leaving the reaction solution, decanting and filtering it to give a transparent filtrate, distilling the solvent away from the filtrate, and heating and vacuum-drying thereof.
Dependencies are inferred from the claim text.