Preparation method for 2-4-6-trimethylbenzoyl chloride

Abstract

The invention discloses a preparation method for 2-4-6-trimethylbenzoyl chloride. The preparation method comprises the following steps: step 1, adding 1000 to 2000 parts by weight of thionyl chlorideinto an acyl chloride synthesis kettle; step 2, controlling the temperature of the acyl chloride synthesis kettle at 0 to 100 DEG C, slowly adding 500 to 1500 parts by weight of 2-4-6-trimethylbenzoicacid into the acyl chloride synthesis kettle, after feeding is completed, heating the acyl chloride synthesis kettle to a reflux state, and maintaining the temperature at 50 to 150 DEG C for 2 to 8 hours; step 3, after heat preservation is completed, allowing the reflux state of the acyl chloride synthesis kettle to be switched to the state of thionyl chloride recovery, wherein recovered thionylchloride is used for synthesis of the next batch of acyl chloride, and the recovery temperature is controlled to be 50 to 200 DEG C; and step 4, after recovery is completed, transferring an acyl chloride crude product in the acyl chloride synthesis kettle to an acyl chloride rectifying tower, and evaporating acyl chloride under a negative pressure so as to obtain a 2-4-6-trimethylbenzoyl chloridefinished product. According to the method provided by the invention, the reaction is rapid; hydrochloric acid and sodium sulfite appearing in the reaction are recovered; and the 2-4-6-trimethylbenzoylchloride is distilled out through rectification, so the purity of a product is guaranteed.

Description

technical field

[0001] The invention relates to the field of chemical industry, in particular to a preparation method of 2-4-6-trimethylbenzoyl chloride. Background technique

[0002] 2,4,6-Trimethylbenzoyl chloride has a wide range of uses. It is used as a photoinitiator in photopolymerizable materials, unsaturated resin models and recording materials; it is used as a stabilizer in plastics and paints to improve its light resistance , heat resistance; in medicine, it is used to prepare antibiotics and antihistamines. It can be used to prepare coatings, dyes, moldings, adhesives, composite fiber materials, etc. However, the reaction in the existing 2,4,6-trimethylbenzoyl chloride synthesis process is slow, and the obtained product is not pure. In addition, the by-products in the reaction are not fully recycled, which not only easily causes environmental pollution, but also wastes resources. Contents of the invention

[0003] The purpose of the present invention is to ove...

Examples

Embodiment 1

[0015] Put 1000kg of thionyl chloride into the acid chloride synthesis kettle, start the hydrogen chloride and sulfur dioxide absorption system, and prepare hydrochloric acid and sodium sulfite. Control the temperature of the acid chloride synthesis kettle at 25°C, slowly add 500kg of 2-4-6-trimethylbenzoic acid into the acid chloride synthesis kettle, after the feeding is completed, the acid chloride synthesis kettle is heated to a reflux state, kept at 50°C for 2 hours, and kept At the end, switch the reflux state of the acid chloride synthesis tank to the recovery of thionyl chloride, and the recovered thionyl chloride is used for the synthesis of the next batch of acid chlorides. The recovery temperature is controlled at 60°C. In the rectifying tower, the acid chloride is distilled under negative pressure to obtain the finished product of 2-4-6-trimethylbenzoyl chloride with a purity of 98.9%.

[0016] The reaction formula is as follows:

[0017]

Embodiment 2

[0019] Put 1500kg of thionyl chloride into the acid chloride synthesis kettle, start the hydrogen chloride and sulfur dioxide absorption system, and prepare hydrochloric acid and sodium sulfite. Control the temperature of the acid chloride synthesis kettle at 50°C, slowly add 1000kg of 2-4-6-trimethylbenzoic acid into the acid chloride synthesis kettle, after the feeding is completed, the acid chloride synthesis kettle is heated to a reflux state, kept at 80°C for 4 hours, and kept At the end, switch the reflux state of the acid chloride synthesis tank to the recovery of thionyl chloride, and the recovered thionyl chloride is used for the synthesis of the next batch of acid chlorides. The recovery temperature is controlled at 80°C. In the rectifying tower, the acid chloride is evaporated under negative pressure to obtain the finished product of 2-4-6-trimethylbenzoyl chloride with a purity of 98.7%.

Embodiment 3

[0021] Preparation of 2-4-6-trimethylbenzoyl chloride

[0022] Put 2000kg of thionyl chloride into the acid chloride synthesis kettle, start the hydrogen chloride and sulfur dioxide absorption system, and prepare hydrochloric acid and sodium sulfite. Control the temperature of the acid chloride synthesis kettle at 80°C, slowly add 1500kg of 2-4-6-trimethylbenzoic acid into the acid chloride synthesis kettle, after the feeding is completed, the temperature of the acid chloride synthesis kettle is raised to a reflux state, and the temperature is kept at 100°C for 6 hours, and the heat preservation End, switch the reflux state of the acid chloride synthesis tank to the recovery of thionyl chloride, the recovered thionyl chloride is used for the next batch of acid chloride synthesis, the recovery temperature is controlled at 100 °C, and the recovery is completed, the crude acid chloride in the acid chloride synthesis tank is transferred to the acid chloride In the rectifying tower...

technical field

[0001] The invention relates to the field of chemical industry, in particular to a preparation method of 2-4-6-trimethylbenzoyl chloride. Background technique

[0002] 2,4,6-Trimethylbenzoyl chloride has a wide range of uses. It is used as a photoinitiator in photopolymerizable materials, unsaturated resin models and recording materials; it is used as a stabilizer in plastics and paints to improve its light resistance , heat resistance; in medicine, it is used to prepare antibiotics and antihistamines. It can be used to prepare coatings, dyes, moldings, adhesives, composite fiber materials, etc. However, the reaction in the existing 2,4,6-trimethylbenzoyl chloride synthesis process is slow, and the obtained product is not pure. In addition, the by-products in the reaction are not fully recycled, which not only easily causes environmental pollution, but also wastes resources. Contents of the invention

[0003] The purpose of the present invention is to ove...

Examples

Embodiment 1

[0015] Put 1000kg of thionyl chloride into the acid chloride synthesis kettle, start the hydrogen chloride and sulfur dioxide absorption system, and prepare hydrochloric acid and sodium sulfite. Control the temperature of the acid chloride synthesis kettle at 25°C, slowly add 500kg of 2-4-6-trimethylbenzoic acid into the acid chloride synthesis kettle, after the feeding is completed, the acid chloride synthesis kettle is heated to a reflux state, kept at 50°C for 2 hours, and kept At the end, switch the reflux state of the acid chloride synthesis tank to the recovery of thionyl chloride, and the recovered thionyl chloride is used for the synthesis of the next batch of acid chlorides. The recovery temperature is controlled at 60°C. In the rectifying tower, the acid chloride is distilled under negative pressure to obtain the finished product of 2-4-6-trimethylbenzoyl chloride with a purity of 98.9%.

[0016] The reaction formula is as follows:

[0017]

Embodiment 2

[0019] Put 1500kg of thionyl chloride into the acid chloride synthesis kettle, start the hydrogen chloride and sulfur dioxide absorption system, and prepare hydrochloric acid and sodium sulfite. Control the temperature of the acid chloride synthesis kettle at 50°C, slowly add 1000kg of 2-4-6-trimethylbenzoic acid into the acid chloride synthesis kettle, after the feeding is completed, the acid chloride synthesis kettle is heated to a reflux state, kept at 80°C for 4 hours, and kept At the end, switch the reflux state of the acid chloride synthesis tank to the recovery of thionyl chloride, and the recovered thionyl chloride is used for the synthesis of the next batch of acid chlorides. The recovery temperature is controlled at 80°C. In the rectifying tower, the acid chloride is evaporated under negative pressure to obtain the finished product of 2-4-6-trimethylbenzoyl chloride with a purity of 98.7%.

Embodiment 3

[0021] Preparation of 2-4-6-trimethylbenzoyl chloride

[0022] Put 2000kg of thionyl chloride into the acid chloride synthesis kettle, start the hydrogen chloride and sulfur dioxide absorption system, and prepare hydrochloric acid and sodium sulfite. Control the temperature of the acid chloride synthesis kettle at 80°C, slowly add 1500kg of 2-4-6-trimethylbenzoic acid into the acid chloride synthesis kettle, after the feeding is completed, the temperature of the acid chloride synthesis kettle is raised to a reflux state, and the temperature is kept at 100°C for 6 hours, and the heat preservation End, switch the reflux state of the acid chloride synthesis tank to the recovery of thionyl chloride, the recovered thionyl chloride is used for the next batch of acid chloride synthesis, the recovery temperature is controlled at 100 °C, and the recovery is completed, the crude acid chloride in the acid chloride synthesis tank is transferred to the acid chloride In the rectifying tower...

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