CN-122010772-A - Rapid conversion method for continuous production of diazonium salt

CN122010772ACN 122010772 ACN122010772 ACN 122010772ACN-122010772-A

Abstract

The invention discloses a rapid conversion method for continuous production of diazonium salt, which comprises the steps of dissolving an amide raw material in a polar solvent, adding acid to obtain an amide salt solution, dissolving sodium nitrite in water to obtain a sodium nitrite aqueous solution, constructing a reaction system in a reaction kettle, synchronously dripping the amide salt solution and the sodium nitrite aqueous solution into the reaction system according to a set proportion, carrying out conversion reaction on the amide salt solution and the sodium nitrite aqueous solution in the reaction kettle through automatic control when synchronously dripping the amide salt solution and the sodium nitrite aqueous solution according to a certain proportion to generate diazonium salt, carrying out instant conversion reaction on the diazonium salt generated in the reaction kettle and the reaction system to obtain a rapid conversion reaction mixture, and treating and separating the rapid conversion reaction mixture to obtain a target product. The invention solves the safety problems of diazonium salt manufacture, storage, transportation and use, greatly improves the yield of diazotization and the next reaction, has high automation degree and can achieve the aim of eliminating the danger of diazonium salt.

Inventors

WANG YUTING
LIU WENBO
DONG JIBO
DENG SHUAI

Assignees

威海韩孚生化药业有限公司

Dates

Publication Date: 20260512
Application Date: 20260126

Claims (10)

1. A rapid conversion process for continuous production of diazonium salts comprising: S100, dissolving an amide raw material in a polar solvent, adding acid to obtain an amide salt solution, and dissolving sodium nitrite in water to obtain a sodium nitrite aqueous solution; S200, adding a bottom system material and a solvent for carrying out conversion reaction with diazonium salt into a reaction kettle, and carrying out temperature regulation and stirring preparation on the reaction kettle to construct a reaction system; S300, synchronously dripping the amide salt solution and the sodium nitrite aqueous solution into the reaction system according to a set proportion; S400, in the synchronous dropwise adding process, through automatic control, enabling the amide salt solution to react with the sodium nitrite aqueous solution in the reaction kettle in a conversion way to generate diazonium salt; S500, after the diazonium salt is generated in the reaction kettle, the diazonium salt is subjected to instant conversion reaction with the reaction system without being separated separately, so that a rapid conversion reaction mixture is obtained; S600, treating the rapid conversion reaction mixture, and separating to obtain a target product.
2. The rapid conversion process for continuous production of diazonium salts according to claim 1, wherein in S100, said polar solvent comprises at least one of water, ethanol, tetrahydrofuran and DMF.
3. The rapid conversion process for continuous production of diazonium salts according to claim 2, wherein in S200 said base system material comprises at least one of dicyano-type substrates, dicyano esters, alkynes, active alkenoates and ketones.
4. The rapid conversion method for continuous production of diazonium salts according to claim 3, wherein in S400, said conversion reaction comprises at least one of substitution reaction, condensation reaction, cyclization reaction and deamination reaction.
5. The rapid conversion process for continuous production of diazonium salts according to claim 4, wherein in S400, when said conversion reaction is a deamination reaction, said bottom system material is a sodium phosphite solution; In S500, the reaction route of the instant conversion reaction is as follows: + a phosphorus-containing byproduct, wherein, Is aryl or heteroaryl.
6. The rapid conversion process for continuous production of diazonium salts according to claim 4, wherein in S400, when said conversion reaction is a condensation reaction and a cyclization reaction, said amide starting material is an aromatic amine and said base system material is ethyl 2, 3-dicyanopropionate; in S500, the reaction route of the instant conversion reaction includes: at the temperature of 0-5 ℃, the diazonium salt generated by the conversion reaction and the ethyl 2, 3-dicyanopropionate are subjected to coupling reaction; and (3) dropwise adding ammonia water, adjusting the pH value to 9-10, and carrying out heat preservation reaction at 0-5 ℃ to complete cyclization.
7. The rapid conversion method for continuous production of diazonium salt according to claim 6, wherein in S400, when said amide raw material is an aromatic amine, said aromatic amine is 2, 6-dichloro-4-trifluoromethylaniline; in S500, the target product of the instant conversion reaction is 5-amino-3-cyano-1- (2, 6-dichloro-4-trifluoromethylphenyl) pyrazole.
8. The rapid conversion method for continuous production of diazonium salt according to claim 6, wherein in S500, when said amide raw material is aromatic amine, the raw materials in said reaction kettle comprise the following components in parts by weight: 35-40 parts of aromatic amine; 85-90 parts of 36% concentrated hydrochloric acid; 175-180 parts of ethanol; 25-26 parts of ethyl 2, 3-dicyanopropionate; 10-12 parts of sodium nitrite; 0.1-0.5 parts of urea; 50-55 parts of 25% ammonia water; 380-400 parts of water.
9. The rapid conversion method for continuous production of diazonium salt according to claim 1, wherein in S400, said automation control is controlled by DCS system; The DCS system carries out synchronous linkage adjustment on the real-time temperature of the reaction kettle and the dropping flow of the amide salt solution, and carries out synchronous linkage adjustment on the flow of the sodium nitrite aqueous solution and the flow of the amide salt solution according to a set fixed molar ratio.
10. The rapid conversion process for continuous production of diazonium salts according to claim 1, wherein in S600, said treating said rapid conversion reaction mixture, separating to obtain the target product comprises: And (3) dropwise adding an acid solution into the rapid conversion reaction mixture at the temperature of 0-5 ℃, adjusting the pH value to 7-8, performing reduced pressure distillation to remove ethanol solvent, filtering, flushing a filter cake with water, and drying to obtain a target product solid.

Description

Rapid conversion method for continuous production of diazonium salt Technical Field The invention relates to the technical field of chemical synthesis and safety, in particular to a rapid conversion method for continuous production of diazonium salt. Background Diazotization is used as a basic reaction in fine chemical production, is widely applied to synthesis of intermediates such as dyes, medicines, pesticides and the like, and has great market demands. With the development of the chemical industry towards the intrinsically safe, automatic and continuous directions, the development of a more efficient and safer diazotization process has become a main development trend of the industry. Conventional diazotisation reactions typically employ batch modes of production, which generally involve the preparation and accumulation of diazonium salts at relatively low temperatures, followed by the transfer of the diazonium salt solution to the next process step for substitution, condensation, cyclization, or deamination. However, the prior art has serious safety drawbacks and technical bottlenecks in production practice. Diazotisation is classified as one of 15 dangerous processes specified in the state, and has a core problem in that diazonium salts have extremely poor thermal stability and are extremely liable to undergo severe decomposition or even explosion under the conditions of temperature rise, collision or drying. In the traditional process, the preparation, storage and transportation processes of diazonium salt all have great potential safety hazards, and if the temperature control of the reaction kettle fails and the storage time is too long, heat accumulation is caused, or friction and temperature rise are generated in the transportation process to the elevated tank, the safety accidents are extremely easy to be caused. In addition, existing countermeasures such as emergency shutdown, accelerated cooling or water backup systems and the like often rely on power guarantee extremely, and hundred percent of effectiveness is difficult to ensure in emergency power failure or equipment failure, and particularly for small units with weak power backup capability, the accident risk is higher. In addition to the safety problems, the prior art has obvious defects in terms of reaction efficiency and environmental protection. Taking deamination reaction as an example, the traditional process is easy to lead materials to polymerize to generate tar because diazonium salt is unstable and the reaction speed is difficult to be matched accurately, or serious material-overflowing phenomenon is caused by instant massive release of nitrogen, so that the environment pollution is high, and the product yield is always lower, and is only about 70-75%. In the condensation cyclization reaction, the traditional process has complicated operation steps, involves multiple extractions and material transfer, and further reduces the production efficiency and the yield of finished products. Therefore, a new technology for converting the intrinsic safety type diazonium salt, which can eliminate the accumulation of the diazonium salt from the technical principle, realize the use along with the living and remarkably improve the yield, is urgently needed in the market. Disclosure of Invention The invention aims to provide a rapid conversion method for continuous production of diazonium salt, which is used for solving at least one technical problem, is safe and reliable, is easy to operate, solves the safety problems of diazonium salt manufacture, storage and use, greatly improves the yield of diazotization and the next reaction, has high automation degree, and can achieve the aim of eliminating danger. Embodiments of the present invention are implemented as follows: A rapid conversion process for continuous production of diazonium salts comprising: S100, dissolving an amide raw material in a polar solvent, adding acid to obtain an amide salt solution, and dissolving sodium nitrite in water to obtain a sodium nitrite aqueous solution. S200, adding a bottom system material and a solvent for carrying out conversion reaction with diazonium salt into a reaction kettle, and carrying out temperature regulation and stirring preparation on the reaction kettle to construct a reaction system. S300, synchronously dripping the amide salt solution and the sodium nitrite aqueous solution into the reaction system according to a set proportion. S400, in the synchronous dropwise adding process, through automatic control, the amide salt solution and the sodium nitrite aqueous solution are subjected to conversion reaction in the reaction kettle to generate diazonium salt. S500, after the diazonium salt is generated in the reaction kettle, the diazonium salt is subjected to instant conversion reaction with the reaction system without being separated, and a rapid conversion reaction mixture is obtained. S600, treating the rapid conversion reaction mixture, and separ