Benzoic anhydride detailed comprehensive description

Benzoic anhydride is also called Benzoic acid anhydride by part of people. And it is increasingly popular by people.What’s it the characteristics and nature properities?Now,I will tell you something about them.
Benzoic anhydride is irritant,and it is also moisture sensitive.Generally speaking,it is white to almost white crystals or crystalline.It has highly effects and no negative effects.When benzoic acid with acetic anhydride is heated in the presence of phosphoric acid ,the benzoic anhydride is produced.The detail process is follow.At first,making benzoic acid, b anhydride and syrup shape phosphoric acid to distillation reaction, its temperature is not more than 120 ℃.When it steamed out a certain amount fractions, adding b anhydride to this reaction mixture,repeat this operation all the time.Then,steamed out until the fractions reactants temperature reaches 270 ℃.At last, press distillation decompression fractionation, collect fractions which temperature is 210-220 ℃,and this fractions is the benzoic acid anhydride rude products,then,the finished product is appeared after heavy crystallization. It is soluble in alcohol, ether, chloroform, propanol, ice hyaluronic acid, benzene.But it is not easy soluble in water,it is quite stable for water and cold alkali.It can be hydrolyzed by boiling alkali metal carbonate and alkali.However, benzoic acid anhydride is hardly soluble in water,and it is colorless inclined square crystals. Benzoic acid anhydride is soluble in ethanol, chloroform, acetone, ethyl acetate, benzene, toluene.But how does it produce?It is always produced by benzoic acid and acetic anhydride under the presence of phosphate. The crude benzoic anhydride contains a little of an oily impurity.And this oily impurity benzoic anhydride can cause the goods turn to yellow.It can be recrystallized by dissolving in benzene.Then,adding enouth petroleum ether ,the reason is that the yellow of it begin to turn cloudiness and it becames chilling.
As far as I know,benzoic anhydride has outstanding applications.First,it can be used as synthetic organic intermediates.A lot of customers buy this product to process the synthetic organic.If using the benzoic anhydride,the progress will be very good.Second,it can be use in pharmaceutical, dye.Most of all,it can also be used as antiseptic, benzene acylating agent, softener.At the same time,it can be used for water analysis.When you are in synthesis of lactones,you also can use it as a coupling reagent.For instance,it is a procedure for synthesis of a 29-membered macrolactone.Using the benzoic anhydrides will make the reaction very effective under mile conditions. Medium-sized lactones is the highly strained cyclic compounds because of the reaction rapidly proceeding to produce the monomeric compounds.The reason why the synthesis of complex molecules has so outstanding efficiency is that benzoic anhydrides have been added in.
In fact,benzoic anhydride and benzoic acid has many differences.As we all know, benzoic acid is a colorless crystalline solid, as a matter of fact,it is the simplest aromatic carboxylic acid. It is formed by oxidation of toluene with oxygen. It is really economic,because the people who had bought it can know that it is not expensive.At the same time, it also has many applications which is the same as benzoic anhydride.As far as I know,it is widely known as chemical standard to determine the heat of capacity of a bomb calorimeter. It is used to make a lot of chemicals.And it can treat the fungal skin diseases,such as ringworm. It is a ingredient in tincture of benzoin and Friar's balsam. It is used as antiseptics and inhalant decongestants for a long time .When benzoic acid and benzoyl chloride are mixtured to reaction,it will produce the benzoic anhyride.
In the modern word,benzoic anhyride has a good sales in the market.Because it can make a lot of advantages to the producer,such as sythetic organic producer.