Study On The Synthesis Of Isovanillin From P-hydroxybenzaldehyde

Isovanillin, 3-hydroxy-4-methoxybenzaldehyde, is an important raw material in the food additives industry with rich milk flavor. It’s used as a flavoring agent and sweetener in desserts and tobacco industry, as an important product in fine hemical industry, as an additive in cosmetics and skin care products, and in agricuture for regulating plant growth, etc. Isovanillin with active hydroxyl and aldehyde, widely used in the food and pharmaceutical industries as a medical intermediate. Synthesis and applications of isovanillin has become a hot spot due to the market’s increasing demand. This paper studies three different routes to the synthesis of isovanillin using p-hydroxybenzaldehyde as raw materials.1、The first part, Through a summary of domestic and foreign references, we outlined the physicochemical properties and the main applications of isovanillin and p-hydroxybenzaldehyde. Then we summarized, analyzed and evaluated the craft ways of synthesizing isovanillin. Finally summarized the purpose and significance of this article.2、The second part, the experimental section. With p-hydroxybenzaldehyde as a starting material, we studied three different routes to synthesis isovanillin. The main reactions during the experiment including: methylation, bromination, hydrolysis of halogenated aromatic, alkoxylation, hydrolysis of aromatic ether. Various conditions and reaction yield are optimized by single factor experiment. We outlined the mechanism of each step in experimental then the experimental results are analyzed and discussed. TLC, HPLC analysis conditions of each reaction steps have been established to monitor the reaction and determine the final quality of the products.By 1H NMR, MS, melting point determination and comparison of references, the product structure of each synthetic route has been confirmed.3、The third part, we summarized the three synthetic routes respectively, and elucidated the follow-up work to be undertaken in the future.