Studies On The Organic Reactions Catalyzed By Solid Acids Or Solid Bases & Structural Analysis

This thesis consists of four parts.In the first part. Solid superacid TiO2/SO4 2-" is found to be cheap solid acidic catalysts for many organic reactions, it has much more efficient behavior in catalysis and simple work-up than conventional counterparts. TiO2/SO4 2 as an efficient and convenient catalyst for the preparation of aromatic oximes has been presented. It is well known that traditional acidic catalysts such as sulfuric acid, phosphoric acid and hydrochloric acid can cause severe environmental problems. The present methods have the additional advantages of non-corrosivity, mild reaction conditions, high yield and selectivity, easy of set-up and work-up over the class methods.In the second part, TiO2/SO4 2-", An efficient catalyst for the methoxymethylation of alcohols Dimethoxymethyl ethers are prepared by condensation of alcohols and dimethoxymethane and it gives satisfactory results. The typical .advantages of the catalyst are easy and simple operation in the workup, non-toxic, non-corrosive, recyclable, more economical and environmentally friendly.In the third part, Coumarins were successfully synthesized by reaction of phenols with ethyl acetoacetate or methyl acetoacetate in the presence of ZrO2/SO4 2- or TiO2/SO4 2-solid superacid. The scope and limitation of the method have been investigated. Coumarins exhibit useful and diverse biological activity such as molluscacides, have anthelmintic, hypnotic and insecticidal properties, or serve as fluorescent brighteners. In this paper we have demonstrated a facile method for the formation of coumarins.In the fourth part, Studying on the condensation of ethyl cyanoacetate with aromatic aldehydes catalyzed by Al2O3-OK solid base in.ethanol results ethyl a-cyanocinnamates in 80-99% yields, alpha-cyanocinnamates are a kind of useful organic compounds for they can "be used as ultraviolet filter composition for protecting light-sensitive foods, wood-product, paper, dyes, fibers, plastics etc. The obvious advantage of solid base is operational simplicity and environmental friendly.