Views: 5 Author: Site Editor Publish Time: 2022-09-05 Origin: Site
Phenol, also known as carbolic acid, is a basic organic chemical raw material. It has a wide range of uses in the plastic industry, pharmaceutical industry, pesticide industry and dye industry. Chlorinated derivatives of p-chlorophenol, 2 Chlorophenol, 2,4-dichlorophenol, 2,6-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol and other phenols can be prepared from phenol by direct chlorination with chlorine gas or by other chemical processes. 2 Chlorophenol is a colorless to yellowish brown liquid with unpleasant and irritating odor. The relative density is 1.265 (15.5 ℃), the melting point is 7 ℃, and the boiling point is 175 ℃. Slightly soluble in water, soluble in ethanol, ether and sodium hydroxide solutions. It can volatilize together with water vapor. And is prepared by chlorinating and separating phenol. For organic synthesis and dye making.
2 Chlorophenol can be used to produce the intermediate chloroformic acid 2 Chlorophenol, the intermediate of carbamate insecticide harmcarb, the pharmaceutical intermediate catechol, and the acid-base indicator chlorophenol red.
(l)O-chlorophenyl chloroformate was synthesized from 2 Chlorophenol by photovaporization. Uses: pesticide intermediates and other fine chemical intermediates.
(2) Catechol is obtained from 2 Chlorophenol by hydrolysis and esterification. This product is used to manufacture berberine and isoprenaline in the pharmaceutical industry. In the perfume industry, it is used to synthesize vanillin, ethyl vanillin, capsaicin, etc., and also to produce dyes.In China, the process for preparing catechol from phenol via hydroxylation has been developed and mature, and the industrial production has been realized. The development conditions are mature, and the raw materials hydrogen peroxide and phenol are sufficient, so it can be vigorously developed. China's pesticides are in a period of renewal, and a number of carbamate varieties with low toxicity and high efficiency, such as Vedan, will continue to be developed.Propoxur is a non inhalable insecticide with fumigation effect. Its efficacy is similar to that of DDVP, but its toxicity is very low. Propoxur is one of the excellent varieties recommended by the World Health Organization for the control of household pests and storage pests. It has a good development prospect.
(3) Chlorophenol red is obtained by heating o-sulfobenzoic acid and 2 Chlorophenol at 130 ℃ and recrystallizing with ice ester acid. This product is mainly used as acid-base indicator.
(4) Prochlorophos was obtained from 2 Chlorophenol through O-substitution, and then reacted with 0-ethyl-s-propyl thiophanylin phthalein chloride under the action of acid dressing. Propofos is a non inhaled broad-spectrum insecticide with contact and stomach toxicity, which can control harmful insects and waxes in cotton and vegetable fields.
(5) Metoclopramide is prepared by the reaction of 2 Chlorophenol with CH3NCO. Promethazir has a quick acting effect and is effective against rice leafhoppers and rice planthoppers. The residual effect period is short, and cooling does not affect the effect.
(l) Sodium phenolate is prepared by chlorination and acid precipitation of sodium phenolate.
(2) In the traditional phenol chlorination method, phenol is obtained by chlorination and distillation in the solvent benzene. At the same time, p-chlorophenol and 2,4-dichlorophenol are also generated in the chlorination reaction. They are collected as high boiling substances during vacuum fractionation and can be used as by-products after separation. The yield of 2 Chlorophenol (mass fraction above 95%) is nearly 50%, and the yield of p-chlorophenol (mass fraction above 95%) is about 25.5%.
(3) Phenol catalytic chlorination is a selective chlorination of phenol in the solvent tetrachloroethylene under specific catalyst conditions. Obtained by rectification and purification. The Research Institute of chemical engineering of Tianjin University has successfully developed the process of synthesizing 2 Chlorophenol by catalytic chlorination of phenol. The Research Institute of Qingdao Jiaonan chemical plant has also carried out trial production according to European patents, and the phenol conversion rate has reached 75%, which has been applied to industrial production.