A kind of preparation method of 3,5-dichlorobenzoyl chloride

Abstract

The invention discloses a preparation method of 3,5-dichlorobenzoyl chloride. The preparation method includes subjecting benzoic acid and a sulfonating agent to sulfonation reaction to obtain 3,5-disulphonatobenzoate; enabling the 3,5-disulphonatobenzoate to react with a chlorinating agent to obtain 5-chloroformyl m-benzenedisulfonyl chloride; subjecting the 5-chloroformyl m-benzenedisulfonyl chloride to sulfur dioxide removal so as to obtain the 3,5-dichlorobenzoyl chloride. The preparation method has the advantages of high product yield, high product purity, environment friendliness and low production cost.

Description

field of invention

[0001] The invention belongs to the field of organic chemical synthesis, and relates to a preparation method of 3,5-dichlorobenzoyl chloride. Background technique

[0002] 3,5-Dichlorobenzoyl chloride is an important pesticide, medicine and dye intermediate. In the production of pesticides, 3,5-dichlorobenzoyl chloride can be benzoylated with methionine and its ether in a sodium hydroxide solution environment, and the obtained derivatives can promote plant growth, improve plant conditions, or make pesticides. As a pharmaceutical intermediate, different derivatives of 3,5-dichlorobenzoyl chloride can treat different diseases. The product of its reaction with a mixture of tropine and hydrogen chloride can be used to prepare a class of drugs for the treatment of human headaches. Very good, the drug is stable and has no side effects; 3,5-dichlorobenzoyl chloride can also be used to prepare tribenzoyl azide as a drug for balancing antidiuretic hormone; the pr...

Examples

Embodiment 1

[0046] Add 208g of benzoic acid into the flask, raise the temperature to 140°C, add 420g of chlorosulfonic acid, maintain the reaction temperature at 140-180°C, and keep the temperature for 10h. Cool down to 120°C, add 1080g of phosphorus pentachloride, raise the temperature to 130-150°C, and keep the temperature for 6h. Then the temperature was raised to 185°C, chlorine gas was introduced under the reaction liquid surface, and sulfur dioxide gas escaped immediately. After 10 hours of reaction, no sulfur dioxide was released. Cool to room temperature and distill under reduced pressure to obtain 297 g of 3,5-dichlorobenzoyl chloride product with a yield of 83.6%, wherein the content of 3,5-dichlorobenzoyl chloride is 99.1%.

Embodiment 2

[0048] Add 208g of benzoic acid in the flask, then add 10g of concentrated sulfuric acid, raise the temperature to 130°C, and start stirring. Slowly add sulfur trioxide dropwise. During the dropwise addition, there is no charging caused by the addition of sulfur trioxide during the reaction, and there is no overheating phenomenon during stirring. The reactant has good solubility and normal viscosity during stirring. The dropping temperature was kept at 130-180° C., and the total amount of dropping was 300 g. After the dropwise addition, the reaction temperature was maintained at 190-210° C., and the holding time was 12 hours. Cool down to 120°C, add 1100g of phosphorus pentachloride, raise the temperature to 130-150°C, and keep reflux for 8h. After the reflux was completed, the temperature was raised to 180°C, and chlorine gas was introduced below the reaction liquid level, and sulfur dioxide escaped immediately, and no gas escaped after 12 hours of reaction. Cool to room te...

Embodiment 3

[0050] Add 208g of benzoic acid into the flask, raise the temperature to 140°C, add 450g of chlorosulfonic acid, maintain the reaction temperature at 140-180°C, and keep the temperature for 12h. After cooling down to 120°C, 1000g of thionyl chloride was added dropwise. During the dropwise addition, the temperature was controlled at 150-160°C and the pressure was 0.3-0.4MPa. After the dropwise addition, keep reflux for 8h. After the reflux was completed, the temperature was raised, and chlorine gas was introduced, and sulfur dioxide escaped immediately, and the reaction temperature was maintained at 170°C. After maintaining the temperature for 12 hours, no sulfur dioxide escaped. Cool to room temperature and distill under reduced pressure to obtain 320 g of 3,5-dichlorobenzoyl chloride product with a yield of 90.1%, wherein the content of 3,5-dichlorobenzoyl chloride is 99.3%.

field of invention

[0001] The invention belongs to the field of organic chemical synthesis, and relates to a preparation method of 3,5-dichlorobenzoyl chloride. Background technique

[0002] 3,5-Dichlorobenzoyl chloride is an important pesticide, medicine and dye intermediate. In the production of pesticides, 3,5-dichlorobenzoyl chloride can be benzoylated with methionine and its ether in a sodium hydroxide solution environment, and the obtained derivatives can promote plant growth, improve plant conditions, or make pesticides. As a pharmaceutical intermediate, different derivatives of 3,5-dichlorobenzoyl chloride can treat different diseases. The product of its reaction with a mixture of tropine and hydrogen chloride can be used to prepare a class of drugs for the treatment of human headaches. Very good, the drug is stable and has no side effects; 3,5-dichlorobenzoyl chloride can also be used to prepare tribenzoyl azide as a drug for balancing antidiuretic hormone; the pr...

Examples

Embodiment 1

[0046] Add 208g of benzoic acid into the flask, raise the temperature to 140°C, add 420g of chlorosulfonic acid, maintain the reaction temperature at 140-180°C, and keep the temperature for 10h. Cool down to 120°C, add 1080g of phosphorus pentachloride, raise the temperature to 130-150°C, and keep the temperature for 6h. Then the temperature was raised to 185°C, chlorine gas was introduced under the reaction liquid surface, and sulfur dioxide gas escaped immediately. After 10 hours of reaction, no sulfur dioxide was released. Cool to room temperature and distill under reduced pressure to obtain 297 g of 3,5-dichlorobenzoyl chloride product with a yield of 83.6%, wherein the content of 3,5-dichlorobenzoyl chloride is 99.1%.

Embodiment 2

[0048] Add 208g of benzoic acid in the flask, then add 10g of concentrated sulfuric acid, raise the temperature to 130°C, and start stirring. Slowly add sulfur trioxide dropwise. During the dropwise addition, there is no charging caused by the addition of sulfur trioxide during the reaction, and there is no overheating phenomenon during stirring. The reactant has good solubility and normal viscosity during stirring. The dropping temperature was kept at 130-180° C., and the total amount of dropping was 300 g. After the dropwise addition, the reaction temperature was maintained at 190-210° C., and the holding time was 12 hours. Cool down to 120°C, add 1100g of phosphorus pentachloride, raise the temperature to 130-150°C, and keep reflux for 8h. After the reflux was completed, the temperature was raised to 180°C, and chlorine gas was introduced below the reaction liquid level, and sulfur dioxide escaped immediately, and no gas escaped after 12 hours of reaction. Cool to room te...

Embodiment 3

[0050] Add 208g of benzoic acid into the flask, raise the temperature to 140°C, add 450g of chlorosulfonic acid, maintain the reaction temperature at 140-180°C, and keep the temperature for 12h. After cooling down to 120°C, 1000g of thionyl chloride was added dropwise. During the dropwise addition, the temperature was controlled at 150-160°C and the pressure was 0.3-0.4MPa. After the dropwise addition, keep reflux for 8h. After the reflux was completed, the temperature was raised, and chlorine gas was introduced, and sulfur dioxide escaped immediately, and the reaction temperature was maintained at 170°C. After maintaining the temperature for 12 hours, no sulfur dioxide escaped. Cool to room temperature and distill under reduced pressure to obtain 320 g of 3,5-dichlorobenzoyl chloride product with a yield of 90.1%, wherein the content of 3,5-dichlorobenzoyl chloride is 99.3%.