改进的Sommelet方法合成芳香醛的研究有机化学专业论文.docx

湘潭大学 湘潭大学 2011 届硕士研究生毕业论文 II II Abstract Aromatic aldehydes range widely in nature, not only are they used widespreadly as organic intermediates in organic synthesis, but also they are important intermediate -s in the metabolic process of plants and animals. Therefore, they have a wide-ranging market prospect, there are many kinds of methods for synthesis of aromatic aldehydes, and the Sommelet reaction which is regarded as a important method was studied and applied. Sommelet reaction is an important and effective method for synthesis of aromatic aldehydes, close attention is paid to it because of its rawmaterials are low-cost and facile, the operation is simple, it has been widely used in the synthesis of aldehydes. traditional Sommelet reaction was reported like this: benzyl halides were treated with hexamethylenetetramine, with aqueous acetic acid as solvent, and whether the aldehydes were obtained or not depends on the value of pH of the solution, only when the value of pH was between 3～6, followed by hydrolysis to yield corresponding aromatic aldehydes. although many people has set out to explore and study the best conditions of synthesis of aldehydes utilizing traditional Sommelet reaction, However, this method suffered from one or more disadvantages. in order to overcome these disadvantageous results, this paper will study the improvement of the Sommelet method, compared with traditional method, the advantages of this method are as following: First, in the traditional Sommelet reaction, the yields were very low, it was inevitable that the side reactions would happen, such as Delepine reaction. and there were many complicated components, so it was difficult to isolate the target products form the system. However, it gave good yields and purity utilizing improved Sommelet reaction. For example, in the synthesis of 2,5-dimethyl-1,4-benzenedicarbo -xaldehyde, according to relevant repord, the best yield was 57%, while in the improved method, the yield rised