The method of preparing phenylacetic acid
Phenylacetic acid, an organic acid, is also used in the field of chemical medicine, and has a wide range of uses. The method of its preparation is described in this article.
One method is to use phenylacetonitrile as the starting material. First take an appropriate amount of phenylacetonitrile, put it in a kettle, add water and acid, such as sulfuric acid. The temperature is controlled at a suitable degree, and it is often heated to boil to make it hydrolyzed. In the reaction, phenylacetonitrile encounters water and acid, and the nitrile group gradually converts to a carboxyl group, and then obtains phenylacetic acid. After the reaction is completed, the product can be separated and purified by distillation and extraction, and pure phenylacetic acid can be obtained.
And benzyl cy Benzyl cyanide can also obtain phenylacetic acid by alkaline hydrolysis. In the reactor, add benzyl cyanide, alkali solution, such as sodium hydroxide solution. Heat up and stir to promote the reaction. When the reaction is over, the reaction solution is acidified to precipitate phenylacetic acid. After filtration, washing, drying and other processes, the finished product of phenylacetic acid is obtained.
Furthermore, styrene is used as the starting material. Styrene is first hydroformylated with carbon monoxide and water under the action of a specific catalyst to obtain phenylmalonaldehyde. Next, phenylmalonaldehyde is oxidized and can be converted into phenylacetic acid. This way requires good control of the reaction conditions. The choice of catalyst, the adjustment of temperature and pressure are all related to the yield and purity of the product.
Preparation of phenylacetic acid, all methods have advantages and disadvantages. Or the raw materials are easy to buy, but the reaction is complicated; or the yield is high, but the cost is not cheap. To get the best method, consider the actual needs, weigh the raw materials, cost, process difficulty and many other factors, and choose carefully.
