Synthesis And Characterization Of Salicylaldehyde Schiff Base

Because of the unique C=N bond, and showing special properties when combine with different characteristics groups, Schiff bases have a wide range of applications in medicine, catalysis, analysis, photochromic and anti-corrosion. The metal complexes of chiral Schiff base was used in various reactions as catalysts.This paper mainly studies the synthetic and characterization of two new chiral salicylaldehyde Schiff bases. The synthetic intermediates and final products were characterized by nuclear magnetic resonance spectroscopy and IR spectrum. The specific research content of this paper is as follows:1. We synthesized 3-(2-iodo-ethyl) salicylaldehyde cyclohexanediamine by f our steps, which are Reimer-Tiemman reaction, SN2 reaction, substitution reac tion and amine aldehyde condensation. Main content is as follows:3-(2-hydr oxy) ethyl-salicylaldehyde was synthesized, and the yield of the reaction was i ncreased by adding methanol and an excess of chloroform; 3-(2-chloroethyl) s alicylaldehyde was synthesized. The impact factors of 3-(2-chloroethyl) salicylal dehyde on yield are:the amount of thionyl chloride, catalyst, time and the te mperature.3-(2-iodo-ethyl) salicylaldehyde was synthesized. We studied the main conditions on the effect of the iodine substitution reaction. (1R,2R)-diam inocyclohexane was obtained by splitting the cyclohexanedia-mine; 3-(2-iodo-et hyl)-salicylaldehyde cyclohexanediamine was synthesized. Then we optimized t he reaction from solvent and reaction temperature. The structure of the target product was characterized by nuclear magnetic resonance spectroscopy and IR spectrum.2.2-(5-ethyl iodide)-salicylidene cyclohexanediamine hydrochloride was synt hesized by four steps, which are Reimer-Tiemman reaction, SN2 reaction, sub stitution reaction and amine aldehyde condensation. Main content is as follows: 5-(2-hydroxy) ethyl-salicylaldehyde was synthesized; 5-chloro-ethyl-salicylaldehy de was synthesized; 5-iodo-ethyl-salicylaldehyde was synthesized; (R,R)-1,2-cyc lohexanediamine hydrochloride unilateral was synthesized; 2-(5-ethyl iodide)-sal icylidene cyclohexanediamine hydrochloride was synthesized. Then we we opti mized the experimental conditions from the choice of solvent, water and temp erature. The structure of the target product was characterized by nuclear magn etic resonance spectroscopy and IR spectrum.