The Synthesis Strategy of Aromatic and Aliphatic Sulfonic Acids
In ancient times, the foundation of creation, the beginning of the universe, and the prosperity of all things. The way of chemistry, although the beginning is not far away, has developed rapidly and become more and more delicate. Today, at the mouth of the chemical production workshop in Lingxian County, on the synthesis strategy of aromatic and aliphatic sulfonic acids, the same is true.

#Synthesis of Aromatic Sulfonic Acids
##Sulfonation Reaction
The preparation of aromatic sulfonic acids is the first. Sulfonic acid, fuming sulfuric acid or chlorosulfonic acid are used as sulfonating agents to interact with aromatic hydrocarbons. For example, benzene and concentrated sulfuric acid are co-heated to obtain benzene sulfonic acid. This reaction mechanism is electrophilic substitution. In sulfuric acid molecules, sulfur atoms are electrophilic, attack the electron cloud of the benzene ring, and pass through the intermediate to deproton to form benzene sulfonic acid. The control of reaction conditions is crucial. If the temperature is too low, the reaction will be slow; if the temperature is too high, side reactions will occur, such as polysulfonation and oxidation. Therefore, the temperature must be precisely adjusted according to the activity of aromatic hydrocarbons. And the concentration of sulfuric acid also has an impact. Concentrated sulfuric acid is conducive to the forward reaction, but if the concentration is too high, the cost will increase and the danger will increase.

##Baking sulfonation method
Baking sulfonation is also a method for synthesizing aromatic sulfonic acids. The sulfonate of aromatic amines is used as the raw material, and the aromatic sulfonic acid is obtained by baking and intramolecular rearrangement. In this process, the molecular structure For example, in the preparation of p-aminobenzenesulfonic acid, aniline sulfonic acid is first obtained, and then baked to obtain the target product. Its advantage is that the conditions are mild, there is no need for strong acid and alkali, and the equipment requirements are also low. However, precise temperature control is required, otherwise the product is prone to impurity.

#Synthesis of aliphatic sulfonic acid
#Sulfo oxidation and sulfo chlorination
Synthesis of aliphatic sulfonic acid, sulfo oxidation and sulfo chlorination are important ways. Sulfo oxidizer reacts with sulfur dioxide, oxygen and aliphatic hydrocarbons under the action of an initiator. The initiator induces sulfur dioxide and oxygen to produce free radicals, which react with aliphatic hydrocarbons to obtain aliphatic sulfonic acid. Sulfo chloride reacts with sulfur dioxide, chlorine gas and aliph This second method can introduce sulfonic acid groups into aliphatic hydrocarbons, but the reaction is complex and there are many by-products. In the reaction system, many factors affect the product, such as the proportion of reactants, reaction temperature, and the amount of initiator. If the ratio is out of balance and the temperature is improper, the yield can be reduced and the product is impure.

##Reaction of halogenated alkanes with sulfites
Halogenated alkanes and sulfites can also synthesize aliphatic sulfonic acids. Halogenated alkanes have high activity of halogen atoms and strong nucleophilicity of sulfite ions. The nucleophilic substitution of the two occurs, and the halogen atom is replaced by a sulfonic acid group. This reaction condition is relatively mild and convenient to operate. However, the choice of halogenated alk The length of the carbon chain of the halogenated alkane and the type of halogen atom affect the reaction activity and product structure. Sulfite is impure, and impurities can cause side reactions to occur.

In short, the synthesis of aromatic and aliphatic sulfonic acids has its advantages and disadvantages. Chemists should choose according to raw materials, equipment, cost, product requirements, etc., to carefully study the process and control the reaction conditions, in order to efficiently and high-quality synthesis of sulfonic acids, for the development of chemical industry, add bricks and mortar, promote chemical progress, and benefit the people.