Views:4 Author:Site Editor Publish Time: 2021-06-25 Origin:Site
Ortho-chlorophenol can be used to produce o-chlorobenzoic acid, an intermediate of carbamate insecticide Hami Provox, and a pharmaceutical intermediate of catechol, as well as acid-base indicator chlorophenol red.
(l) O-chlorobenzene chloroformate is unitarily converted from o-chlorophenol through phosgenation to obtain o-chlorophenyl chloroformate. Use as pesticide intermediates and other fine chemical intermediates.
(2) Catechol is obtained by hydrolyzing and esterifying o-chlorophenol as raw material. This product is used in the pharmaceutical industry to manufacture berberine and isoproterenol. In the perfume industry, it is used to synthesize vanillin, ethyl vanillin, piperonal, etc., and can also be used to produce dyes. The total demand for catechol in my country in 2002 was about 900t. At present, my country's catechol production plants are all running at full capacity, and only have an output of 3,500t/a, which is far from meeting the needs. The process of preparing catechol from phenol in my country has been developed and matured, and industrial production has also been realized.
The development conditions have been mature, and the raw materials are sufficient for hydrogen peroxide and phenol, so it can be vigorously developed. Pesticides in my country are in the renewal period. A batch of low-toxic and high-efficiency carbamate varieties such as Pylantan will continue to develop. It is expected that the production capacity of Pyranol in my country will reach 300t in 2002, and catechol will be consumed by then. About 500t. Proxacarb is a non-systemic insecticide with fumigation effect. Its efficacy is similar to that of dichlorvos, but its toxicity is extremely low. It is one of the fine varieties of household pests and storage pest control agents recommended by the World Health Organization. It has a good development prospect . It is estimated that the production capacity of propoxur in my country will reach 1000t in 2002, and it will consume about 650t of catechol. P-tert-butylcatechol is widely used as a polymerization inhibitor, antioxidant and light stabilizer. Only a small number of manufacturers in my country produce about 100t/a. With the localization of catechol, this product will definitely develop better in the future. my country is the main producer and exporter of vanillin in the world. The current total production capacity is about 10,000 t/a, and the annual export is nearly 200 t. With the development of catechol production, vanillin production will gradually adopt new neighbors. Hydroquinone process.
At present, Shanghai Xinhua Perfume Factory and Jilin Chemical Co., Ltd. Auxiliary Factory have adopted this method for production, and the annual consumption of catechol is about 100t. In the future, there will be more room for development in the synthesis of vanillin by the catechol method. Piperonal is a traditional product. In recent years, it has been mainly exported. The annual output is about 300t, which consumes about orot of catechol. It is expected that the amount of catechol consumed in the production of piperonal will not increase too much in the near future.
(3) Chlorophenol red is obtained by heating o-sulfobenzoic acid with o-chlorophenol at 130°C to obtain a crude product, and then recrystallizing it with glacial ester acid. This product is mainly used as an acid-base indicator.
(4) Pronophos is obtained from o-chlorophenol through the Australian generation to obtain o-chloro-p-Aophenol, and then reacts with O-Ethyl-S-Propylthiolanphthalein under the action of an acid application agent. Profenofos is a non-systemic broad-spectrum insecticide with contact killing and stomach poisoning effects. It can control harmful insects and waxes in cotton and vegetable fields.
(5) Lupocarb is derived from the reaction of o-chlorophenol with CH3NCO. Papaver has quick-acting effects and is effective against rice leafhoppers, rice planthoppers, etc. The residual effect period is short, and the cooling does not affect the effect.
(6) The synthesis method of 2,4-dichlorophenoxyacetic acid, using o-chlorophenol as a raw material, firstly react with chloroacetic acid to produce o-chlorophenoxyacetic acid, and then o-chlorophenoxyacetic acid and chlorine are reacted in a mixed solvent 2,4-Dichlorophenoxyacetic acid, the mixed solvent is a mixture of DMF, water and dichloroethane. The invention uses o-chlorophenol as a raw material, which not only provides a way out for o-chlorophenol, but also provides a new idea for the synthesis of 2,4-D. The raw materials are easily available and cheap, and the product production cost is low. The use of mixed solvents improves the selectivity of the reaction, avoids the use of catalysts, and through the coordination of other conditions, the reaction temperature increases the product yield, greatly reducing 2,6-dichlorophenoxyacetic acid and 2,4,6- For the formation of trichlorophenoxyacetic acid, the single-step yield of 2,4-dichlorophenoxyacetic acid can reach more than 95%.