查看更多>>摘要：Solvents have an important effect on the epoxidation of propylene catalyzed by TS-1. The experimental results show that, in different solvents, the catalytic activity of epoxidation is in the following order: methanol > 2-propanol > 2-butanol > acetoni-trile > acetone > tetrahydrofuran. Based on the reaction mechanism, the effects of solvents on the epoxidation were studied from eight aspects, which included the electronic effect, the steric effect, the polarity of solvent, the effect of solvent on sorption and diffusion of reactant, the oxidation of alcohol, the etherification of PO, the deactivation of TS-1 and the solubility of propylene in the solvents. The electronic effect, steric effect and the polarity of solvent were considered to be the main aspects. This work may provide theoretical guidance for choosing solvents for these kinds of reactions and also may serve as basis for further industrialization.
查看更多>>摘要：Based on the SAR (structure activity relation-ship) of TZDs (thiazolidinediones), 3-methyl-1-phenyl-2-pyrazoline-5-one was selected as a substitute for TZD. Compounds of 3-methyl- 1-phenyl-4- {4-[(5-methyl-2-phe-nyloxazol-4-yl)methoxy]benzylene(benzyl) }-2-pyrazol-5-one were designed and synthesized to find some more hypoglycemic active agents and further investigate the SAR of this class of compounds. Butanedione monoxime reacted with (substituted) benzaldehyde via cyclization and chlorination to give 4-(chloromethyl)-5-methyl-2-phenyloxazole derivatives, which condensed with 4-hydroxybenzaldehyde or vanillin, and was followed by the Knoevenagel reaction with 3-methyl-1-phenyl-2-pyrazol-5-one to give compounds Ⅰa-Ⅰh. Compounds Ⅰa-Ⅰh were hydrogenated with Pd-C to giveⅡa-Ⅱh, and their hypoglycemic activity was evaluated with a glucose oxidase kit and insulin load test on normal mice. Sixteen new target compounds were synthesized. All the com-pounds were characterized by 1H NMR, IR, MS and elemental analysis. The preliminary pharmacological tests show that the compounds have good hypoglycemic activity and can enhance the action of insulin, especially Ib, Id and If.
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