Comparison for Synthesis Methods of Indole-3-carboxaldehyde

The synthesis of indole-3-caeboxaldehyde was described starting from indole,and various influence factors were analyzed to the reaction.The yield was 96.4% by method 2 and 29.0% by method 1.The structure of product was determined by1HNMR,13CNMR,MS and IR.These two reactions under different condition was compared,and the better dye crytalline of indole-3-caeboxaldehyde was gotten by the method 2.It was beneficial to reaction yield that the reacted temperature was elevated and decreased the reacted time after phosphorous oxychloride was dropped.Polar solution was good for the reaction,but nonpolar solution was bad for the reaction.Once the reaction stopped,the temparature in mixture was dropped sharply and could decreas the by-products.