碲氢化钠与苯并咪唑盐的反应和醛的合成新方法

The reaction between sodium hydrogen telluride and benzimidazolium salts and a novel synthetic method for aldehydes

1,3-dimethyl-2-substituted benzimidazolium salt can be easily prepared from carboxylic acid,o-phenylenediamine and methyl iodide via cyclization and quarternarization.It reacts with sodium hydrogen telluride in ethanol solution to produce 1,3-dimethyl-2-substituted benzimidazolidine.The reaction mechanism is discussed.Two benzimidazolidines are characterized by means of elemental analysis,IR and 1H NMR.Aldehydes are synthesized by hydrolysis reaction of the benzimidazolidines.Then,a novel synthetic method for aldehydes from the corresponding carboxylic acids via reduction-hydrolysis reaction of benzimidazolium salts is presented.The effect of 2-substituting group of benzimidazolium salts on the yield is discussed.

1,3 -dimethyl -2 -substituted benzimidasolium salt can be easily prepared from carboxylic acid, o -phenylenediamine and methyl iodide via cyclization and quartemarization. It reacts with sodium hydrogen telluride in ethanol solution to produce 1,3 - dimethyl - 2 - substituted benzimidasolidine. The reaction mechanism is discussed. Two benzimidazolidines are characterized by means of elemental analysis, IR and 1H NMR. Aldehydes are synthesized by hydrolysis reaction of the benzimidazolidinea. Then, a novel synthetic method for aldehydes from the corresponding carboxylic acids via reduction -hydrolysis reaction of benzimidasolium salts is presented. The effect of 2 - substituting group of benzimidasolium salts on the yield is discussed.