Novel preparation method of 3,5-dichlorobenzoyl chloride

Abstract

The invention relates to a new preparation method of 3,5-dichlorobenzoyl chloride, which belongs to the technical field of compound synthesis. The new preparation method of 3,5-dichlorobenzoyl chloride of the present invention comprises the following steps: (1) first reaction: anthranilic acid and trifluoroacetic acid are reacted to prepare 2-trifluoroacetamidobenzoic acid; (2) Second reaction: 2‑trifluoroacetamidobenzoic acid reacts with chlorine to prepare 3,5‑dichloro‑2‑trifluoroacetamidobenzoic acid; (3) Third reaction: 3,5‑dichloro‑2‑trifluoro Acetaminobenzoic acid and liquid alkali react to prepare 3,5-dichloro-2-aminobenzoic acid sodium, and then acidify to obtain 3,5-dichloro-2-aminobenzoic acid; (4) The fourth reaction: 3,5-di Chloro-2-aminobenzoic acid reacts with sodium nitrite, hydrochloric acid and isopropanol to prepare 3,5-dichloro-benzoic acid; (5) fifth reaction: 3,5-dichloro-benzoic acid and thionyl chloride reaction to obtain 3,5-dichlorobenzoyl chloride. The method of the invention protects the amino group before chlorination, effectively prevents the oxidation of the amino group, and the chlorination yield is above 95%.

Description

technical field

[0001] The invention relates to the technical field of compound synthesis, in particular to a new preparation method of 3,5-dichlorobenzoyl chloride. Background technique

[0002] 3,5-dichlorobenzoyl chloride is an important pesticide intermediate, its molecular structure is as follows:

[0003] . 3,5-Dichlorobenzoyl chloride has a wide range of uses. It can be used to prepare different substances through different reactions. It is mainly used in the production of pesticides, pharmaceuticals, and dyes. 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 Insecticide. As a pharmaceutical intermediate, different derivatives of 3,5-dichlorobenzoyl chloride can treat different diseases. It reacts with a mixture of tropine and hydrogen chloride to prepare a cla...

Examples

Embodiment 1

[0047] Add 137g of anthranilic acid and 120g of trifluoroacetic acid to a 1000mL four-neck flask, and perform the first reaction at 100°C. Stop the reaction when the impurity peak in liquid chromatography reaches below 0.3%, and obtain 2-trifluoroacetamidobenzoic acid (The required reaction time is about 12h). After the first reaction is over, add 500g of glacial acetic acid to the above-mentioned four-necked bottle, stir well, and then slowly inject 150g of chlorine gas at 40°C to carry out the second reaction, and the peak of 2-trifluoroacetamidobenzoic acid does not turn to 0.1% in liquid chromatography The reaction was stopped at the following time; the required reaction time was about 12 hours. After the second reaction, the product in the four-neck flask was taken out, suction filtered and washed to obtain 3,5-dichloro-2-trifluoroacetylaminobenzoic acid as a solid. Then add 3,5-dichloro-2-trifluoroacetamidobenzoic acid solid into 150g 32% (mass concentration, the same b...

Embodiment 2

[0049]Add 137g of anthranilic acid and 120g of trifluoroacetic acid to a 1000mL four-neck flask, and perform the first reaction at 100°C. Stop the reaction when the impurity peak in liquid chromatography reaches below 0.3%, and obtain 2-trifluoroacetamidobenzoic acid (The required reaction time is about 12h). After the first reaction is over, add 500g of glacial acetic acid to the above-mentioned four-necked bottle, stir well, and then slowly inject 150g of chlorine gas at 40°C to carry out the second reaction, and the peak of 2-trifluoroacetamidobenzoic acid does not turn to 0.1% in liquid chromatography The reaction was stopped at the following time; the required reaction time was about 12 hours. After the second reaction, the product in the four-neck flask was taken out, suction filtered and washed to obtain 3,5-dichloro-2-trifluoroacetylaminobenzoic acid as a solid. Then add 3,5-dichloro-2-trifluoroacetamidobenzoic acid solid into 150g32% liquid caustic soda for the third...

Embodiment 3

[0051] Add 137g of anthranilic acid and 120g of trifluoroacetic acid to a 1000mL four-neck flask, and perform the first reaction at 100°C. Stop the reaction when the impurity peak in liquid chromatography reaches below 0.3%, and obtain 2-trifluoroacetamidobenzoic acid (The required reaction time is about 12h). After the first reaction is over, add 500g of glacial acetic acid to the above-mentioned four-necked bottle, stir well, and then slowly inject 150g of chlorine gas at 40°C to carry out the second reaction, and the peak of 2-trifluoroacetamidobenzoic acid does not turn to 0.1% in liquid chromatography The reaction was stopped at the following time; the required reaction time was about 12 hours. After the second reaction, the product in the four-neck flask was taken out, suction filtered and washed to obtain 3,5-dichloro-2-trifluoroacetylaminobenzoic acid as a solid. Then add 3,5-dichloro-2-trifluoroacetamidobenzoic acid solid into 150g32% liquid caustic soda for the thir...

technical field

[0001] The invention relates to the technical field of compound synthesis, in particular to a new preparation method of 3,5-dichlorobenzoyl chloride. Background technique

[0002] 3,5-dichlorobenzoyl chloride is an important pesticide intermediate, its molecular structure is as follows:

[0003] . 3,5-Dichlorobenzoyl chloride has a wide range of uses. It can be used to prepare different substances through different reactions. It is mainly used in the production of pesticides, pharmaceuticals, and dyes. 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 Insecticide. As a pharmaceutical intermediate, different derivatives of 3,5-dichlorobenzoyl chloride can treat different diseases. It reacts with a mixture of tropine and hydrogen chloride to prepare a cla...

Examples

Embodiment 1

[0047] Add 137g of anthranilic acid and 120g of trifluoroacetic acid to a 1000mL four-neck flask, and perform the first reaction at 100°C. Stop the reaction when the impurity peak in liquid chromatography reaches below 0.3%, and obtain 2-trifluoroacetamidobenzoic acid (The required reaction time is about 12h). After the first reaction is over, add 500g of glacial acetic acid to the above-mentioned four-necked bottle, stir well, and then slowly inject 150g of chlorine gas at 40°C to carry out the second reaction, and the peak of 2-trifluoroacetamidobenzoic acid does not turn to 0.1% in liquid chromatography The reaction was stopped at the following time; the required reaction time was about 12 hours. After the second reaction, the product in the four-neck flask was taken out, suction filtered and washed to obtain 3,5-dichloro-2-trifluoroacetylaminobenzoic acid as a solid. Then add 3,5-dichloro-2-trifluoroacetamidobenzoic acid solid into 150g 32% (mass concentration, the same b...

Embodiment 2

[0049]Add 137g of anthranilic acid and 120g of trifluoroacetic acid to a 1000mL four-neck flask, and perform the first reaction at 100°C. Stop the reaction when the impurity peak in liquid chromatography reaches below 0.3%, and obtain 2-trifluoroacetamidobenzoic acid (The required reaction time is about 12h). After the first reaction is over, add 500g of glacial acetic acid to the above-mentioned four-necked bottle, stir well, and then slowly inject 150g of chlorine gas at 40°C to carry out the second reaction, and the peak of 2-trifluoroacetamidobenzoic acid does not turn to 0.1% in liquid chromatography The reaction was stopped at the following time; the required reaction time was about 12 hours. After the second reaction, the product in the four-neck flask was taken out, suction filtered and washed to obtain 3,5-dichloro-2-trifluoroacetylaminobenzoic acid as a solid. Then add 3,5-dichloro-2-trifluoroacetamidobenzoic acid solid into 150g32% liquid caustic soda for the third...

Embodiment 3

[0051] Add 137g of anthranilic acid and 120g of trifluoroacetic acid to a 1000mL four-neck flask, and perform the first reaction at 100°C. Stop the reaction when the impurity peak in liquid chromatography reaches below 0.3%, and obtain 2-trifluoroacetamidobenzoic acid (The required reaction time is about 12h). After the first reaction is over, add 500g of glacial acetic acid to the above-mentioned four-necked bottle, stir well, and then slowly inject 150g of chlorine gas at 40°C to carry out the second reaction, and the peak of 2-trifluoroacetamidobenzoic acid does not turn to 0.1% in liquid chromatography The reaction was stopped at the following time; the required reaction time was about 12 hours. After the second reaction, the product in the four-neck flask was taken out, suction filtered and washed to obtain 3,5-dichloro-2-trifluoroacetylaminobenzoic acid as a solid. Then add 3,5-dichloro-2-trifluoroacetamidobenzoic acid solid into 150g32% liquid caustic soda for the thir...

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