Method for synthesizing thiophenol with supercritical hydrogen sulfide

Abstract

The invention relates to a phenthiol synthesis method, in particular to a method comprising the following steps that in a high-pressure reaction vessel, hydrogen sulfide takes a contact reaction with chlorobenzene in a supercritical state, wherein the mol ratio of the chlorobenzene to the hydrogen sulfide is 1:1 to 1:10, the reaction temperature is 100 DEG C to 200 DEG C, the reaction pressure is 9 to 25 MPa, and the reaction time is 1 to 10 hours; after the reaction is completed, water is used for washing a reaction mixture; an oil phase is collected; reduced pressure distillation is performed; fraction (10mmHg, 47 to 49 DEG C) is collected; the phenthiol is obtained.

Description

technical field [0001] The invention relates to a method for synthesizing thiophenol by using supercritical hydrogen sulfide as a raw material. Background technique [0002] Thiophenol is a colorless transparent liquid, insoluble in water, easily soluble in organic solvents such as ethanol, and its structural formula is shown in formula S-1. Thiophenol has a wide range of uses and can be used to synthesize pesticides "Kewensan" and "Dichonphos". It is also an intermediate and raw material for rubber accelerators, polymerization inhibitors, antioxidants and dyes; it can also be used to produce local anesthetics, Thiamphenicol, a substitute for chloramphenicol, has important research value. [0003] [0004] At present, the synthesis methods of thiophenol with industrial value are mainly divided into benzenesulfonyl chloride method, chlorobenzene method and phenol method. The benzenesulfonyl chloride method (Ger. (East), 251343, 1987; Jpn.Kokai Tokkyo Koho, 04005271, 1992...

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Problems solved by technology

The benzenesulfonyl chloride method (Ger. (East), 251343, 1987; Jpn.Kokai Tokkyo Koho, 04005271, 1992) usually uses benzene as a raw material to obtain thiophenol through chlorosulfonation and reduction. This method needs to consume a large amount of chlorine Sulfonic acid is highly corrosive, has a long reaction cycle, has many wastes, and is not easy to handle; the chlorobenzene method uses chlorobenzene and hydrogen sulfide as raw materials, and adopts catalytic or non-catalytic reactions to obtain thiophenol. Among them, the catalytic method (Jpn.Kokai Tokkyo Koho , 2010285400, 2010) The reaction temperature is slightly lower (450-500°C), but the catalyst is easily deactivated by sulfur poisoning, and the general lifespan is only about 300 hours. Non-catalytic method (ZhurnalOrganicheskoi Khimii, 22(4), 846-50; 1986) There is no problem of catalyst deactivation, but the reaction temperature is very high (generally exceeding 600 ° C), and the reaction selectivity is low and the product yield is low; -9; 1991; Tetrahedron Letters, 21(32), 3099-100; 1980) to prepare thiophenol, but in essence it is similar to the reaction of chlorobenzene and hydrogen sulfide, and the price of mercaptan is high, the cost of this process The disadvantage is obvious; and the phenol method (US., 4088698,1977; US., 4754072,1987) is to be reacted at high temperature by phenol and hydrogen sulfide, and productive rate is low, and cost is high, and practical value is little

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