Synthesis method of 3,5-dichlorobenzoyl chloride

Abstract

The invention discloses a synthesis method of 3,5-dichlorobenzoyl chloride. The synthesis method comprises the following steps: firstly, carrying out sulfonation reaction by taking benzoyl chloride as a raw material, secondly, conducting catalytic chlorination reaction and thirdly conducting sulfur dioxide removal chlorination reaction. The synthesis method is characterized in that the sulfur dioxide removal chlorination reaction in the third step is carried out under the catalysis of quaternary phosphonium salt. By adopting a method of catalyzing the sulfur dioxide removal chlorination, and compared with the existing technological method, the synthesis method has the characteristics of reducing the reaction temperature, quickening the reaction speed, being higher in the yield and content of products, and the like, and is suitable for industrial production.

Description

technical field

[0001] The invention relates to a fine chemical product, especially a method for preparing a pesticide intermediate 3,5-dichlorobenzoyl chloride. Background technique

[0002] 3,5-Dichlorobenzoyl chloride is an important fine chemical intermediate, especially an important intermediate for the synthesis of herbicides such as propyzamide and oxaziclomefone.

[0003]

[0004]

[0005] The document synthetic route of the reported 3,5-dichlorobenzoyl chloride has the following several kinds:

[0006] 1. U.S. Patent US 3931300, Chemical Engineer (2009, (6), 68-70), German Patent DE 2721133, German Patent DE 2659147, etc. reported that anthranilic acid, p-aminobenzoic acid or their mixtures were chlorinated by chlorinating agents Obtain 3,5-dichloroanthranilic acid, 3,5-dichloro-p-aminobenzoic acid or a mixture of the two, then eliminate the amino group by diazotization reduction to obtain 3,5-dichlorobenzoic acid, and finally chlorinate The chlorination of re...

Examples

Embodiment 1

[0032] Example 1 Heat 140.5g (1.0mol) of benzoyl chloride to 130°C, add 176g (2.2mol) of sulfur trioxide dropwise, and control the dropping for 2 hours. During the dropwise addition, the temperature was gradually raised to 170°C, and continued to be raised to 220°C after the dropwise addition and kept for 16 hours. After cooling to 120°C, 2.4 g of catalyst tri-n-butylamine and 60 mL of cumene were added. Add 218g (2.2mol) of triphosgene in batches and keep the reflux reaction for 3h. The reflux was changed to distillation, and the cumene was distilled out under normal pressure first, then under reduced pressure until the internal temperature was 150°C. The temperature was lowered to 145°C, 3.5 g of methyltriphenylphosphonium bromide was added, and then chlorine gas was passed into the reaction solution under the liquid surface at a rate of 0.35 g / min, and sulfur dioxide gas escaped immediately. After 100 minutes of reaction, sulfur dioxide is no longer emitted. Cooled to...

Embodiment 2

[0033] Example 2 Heat 140.5g (1.0mol) of benzoyl chloride to 130°C, add 176g (2.2mol) of sulfur trioxide dropwise, and control the dropping for 2 hours. During the dropwise addition, the temperature was gradually raised to 170°C, and continued to be raised to 220°C after the dropwise addition and kept for 16 hours. After cooling to 120°C, 2.0 g of catalyst 4-dimethylaminopyridine (DMAP) and 60 mL of mixed xylene were added. Add 218g (2.2mol) of triphosgene in batches and keep the reflux reaction for 3h. The reflux was changed to distillation, and the mixed xylene was distilled out under normal pressure first, then under reduced pressure until the internal temperature was 140°C. Keeping at 140°C, add 3.0 g of benzyltriphenylphosphonium bromide, and then pass chlorine gas under the reaction liquid at a rate of 0.35 g / min, and sulfur dioxide gas will escape immediately. After reacting for 1.5h, no more sulfur dioxide was emitted. Cool to 40°C and distill under reduced pres...

Embodiment 3

[0035] Example 3Heat 140.5g (1.0mol) of benzoyl chloride to 140°C, add 176g (2.2mol) of sulfur trioxide dropwise, and control the dropping for 2 hours. During the dropwise addition, the temperature was gradually raised to 170°C, and continued to be raised to 220°C after the dropwise addition and kept for 16 hours. After cooling to 100°C, 1.1 g of catalyst N-methylmorpholine and 50 mL of p-xylene were added. Add 218g (2.2mol) of triphosgene in batches and keep the reflux reaction for 4h. The reflux was changed to distillation, and p-xylene was distilled out under normal pressure first, then under reduced pressure until the internal temperature was 145°C. Keeping at 145°C, 2.4 g of ethyltriphenylphosphonium bromide was added, and then chlorine gas was passed into the reaction solution under the liquid surface at a rate of 0.4 g / min, and sulfur dioxide gas escaped immediately. After reacting for 90 minutes, sulfur dioxide was no longer emitted. Cool to 50°C and distill under...

technical field

[0001] The invention relates to a fine chemical product, especially a method for preparing a pesticide intermediate 3,5-dichlorobenzoyl chloride. Background technique

[0002] 3,5-Dichlorobenzoyl chloride is an important fine chemical intermediate, especially an important intermediate for the synthesis of herbicides such as propyzamide and oxaziclomefone.

[0003]

[0004]

[0005] The document synthetic route of the reported 3,5-dichlorobenzoyl chloride has the following several kinds:

[0006] 1. U.S. Patent US 3931300, Chemical Engineer (2009, (6), 68-70), German Patent DE 2721133, German Patent DE 2659147, etc. reported that anthranilic acid, p-aminobenzoic acid or their mixtures were chlorinated by chlorinating agents Obtain 3,5-dichloroanthranilic acid, 3,5-dichloro-p-aminobenzoic acid or a mixture of the two, then eliminate the amino group by diazotization reduction to obtain 3,5-dichlorobenzoic acid, and finally chlorinate The chlorination of re...

Examples

Embodiment 1

[0032] Example 1 Heat 140.5g (1.0mol) of benzoyl chloride to 130°C, add 176g (2.2mol) of sulfur trioxide dropwise, and control the dropping for 2 hours. During the dropwise addition, the temperature was gradually raised to 170°C, and continued to be raised to 220°C after the dropwise addition and kept for 16 hours. After cooling to 120°C, 2.4 g of catalyst tri-n-butylamine and 60 mL of cumene were added. Add 218g (2.2mol) of triphosgene in batches and keep the reflux reaction for 3h. The reflux was changed to distillation, and the cumene was distilled out under normal pressure first, then under reduced pressure until the internal temperature was 150°C. The temperature was lowered to 145°C, 3.5 g of methyltriphenylphosphonium bromide was added, and then chlorine gas was passed into the reaction solution under the liquid surface at a rate of 0.35 g / min, and sulfur dioxide gas escaped immediately. After 100 minutes of reaction, sulfur dioxide is no longer emitted. Cooled to...

Embodiment 2

[0033] Example 2 Heat 140.5g (1.0mol) of benzoyl chloride to 130°C, add 176g (2.2mol) of sulfur trioxide dropwise, and control the dropping for 2 hours. During the dropwise addition, the temperature was gradually raised to 170°C, and continued to be raised to 220°C after the dropwise addition and kept for 16 hours. After cooling to 120°C, 2.0 g of catalyst 4-dimethylaminopyridine (DMAP) and 60 mL of mixed xylene were added. Add 218g (2.2mol) of triphosgene in batches and keep the reflux reaction for 3h. The reflux was changed to distillation, and the mixed xylene was distilled out under normal pressure first, then under reduced pressure until the internal temperature was 140°C. Keeping at 140°C, add 3.0 g of benzyltriphenylphosphonium bromide, and then pass chlorine gas under the reaction liquid at a rate of 0.35 g / min, and sulfur dioxide gas will escape immediately. After reacting for 1.5h, no more sulfur dioxide was emitted. Cool to 40°C and distill under reduced pres...

Embodiment 3

[0035] Example 3Heat 140.5g (1.0mol) of benzoyl chloride to 140°C, add 176g (2.2mol) of sulfur trioxide dropwise, and control the dropping for 2 hours. During the dropwise addition, the temperature was gradually raised to 170°C, and continued to be raised to 220°C after the dropwise addition and kept for 16 hours. After cooling to 100°C, 1.1 g of catalyst N-methylmorpholine and 50 mL of p-xylene were added. Add 218g (2.2mol) of triphosgene in batches and keep the reflux reaction for 4h. The reflux was changed to distillation, and p-xylene was distilled out under normal pressure first, then under reduced pressure until the internal temperature was 145°C. Keeping at 145°C, 2.4 g of ethyltriphenylphosphonium bromide was added, and then chlorine gas was passed into the reaction solution under the liquid surface at a rate of 0.4 g / min, and sulfur dioxide gas escaped immediately. After reacting for 90 minutes, sulfur dioxide was no longer emitted. Cool to 50°C and distill under...

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