Study On Novel Chromogenic Crown Ethers And The Synthesis Of Benzimidazoles

This paper is divided into two parts.First, the raw materials of catechol, 2-chloroethanol, diethylene glycol, acenaphthene quinone, 4-bromo-1, 8-naphthalene were used to synthesize two novel chromogenic crown ethers. Such compounds can not only complex metal ions, also colored material. These properties are a reflection of two kinds of structures, but often it is not unrelated to each other. When the change of the intermolecular electron density caused by the complexation of crown ethers and metal ions affects the chromogenic groups, or the chromogenic groups participate in the complexation, color of the complex changes. Their structures were analyzed through 1H NMR. Fluorescence spectra were used to study the ion coordination and recognition performances of one of the two novel chromogenic crown ether compounds.The second part is on the novel synthetic method for Benzimidazole Derivatives. Benzimidazole moieties are extensively found in compounds that used in medicinal chemistry. Benzimidazole derivatives have shown diverse biological and pharmaceutical activities such as antineoplastic and antiulcer activities, antifungal and antiprotozoal infection. We have developed a facile one-pot synthesis of 2-substituted benzimidazoles. Several advantages are contained: (1) Neither metal oxides nor organic oxidizing agents are used, only air (or oxygen) is utilized. (2) UV light was employed as an alternative of general heating so that the reaction can be carried out under mild conditions of r.t.. (3) Nontoxic solvent ethanol is used and little pollution was produced, which provides a GREEN synthetic routine.