The Synthesis Of Several Drug Intermediates Based On Knevenagel Condensation

Knoevenagel Condensation is one of the widely used basic reactions in the application of organic synthetic chemistry which has many virtues such as mild reaction conditions,simple operation.It can create a lack of electronic carbon - carbon double bond to increase the carbon bond and the activity of the condensation production is well.In addition,it can carry out kinds of conversions and has been widely applied in synthetic chemistry.In this paper,we studied the Synthesis of several drug intermediates based on Knevenagel Condensation.The three parts are involved in the following.Partâ… :Synthesis of 3,4,5-Trimethoxycinnamic acidThe paper design a new synthetic routes:3,4,5-three methoxy benzaldehyde was prepared from pyrogallol as the starting material via methylation,Vilsmeier reaction, and then 3,4,5-Trimethoxycinnamic acid was obtained on the basis of Knoevenagel condensation with an overall yield of 79%.This study also explored the factors affecting the yield and to optimize the operation process,providing a reference for its industrialization.This experiment has advantages of mild reaction conditions, technology easy to control and easy product separation,so it is conducive to large-scale production and has an important value.Partâ…¡:Synthesis of cinnamon nitrileIn the solvent-free conditions,cinnamon nitrile was prepared from benzaldehyde as the starting material through Knoevenagel condensation reaction and Krapcho Decarbonylation reaction using Ethylenediamine diethylamino salt(EDDA)as catalyst.The reaction route have advantages of mild reaction conditions,easy to handle and simple manipulation,being effective in reducing pollution and waste of resourcesand in overall of 77%.Partâ…¢:HA 14-1 and coumarin compounds SynthesisIn the solvent-free conditions,we studied three compoments reaction by Knevenagel condensation reaction and Michael addition reaction.Results failed to synthesize HA 14-1 and coumarin compounds.The solvent-free synthetic technique and one-pot synthetic technique will not only avoid the use of conventional poisonous and volatile organic solvents leading to environmentally friendly" green chemistry", but also save the expenditure and find a borad application in organic synthesis...