Method for preparing 4'-chloro-2-nitrobiphenyl

Abstract

The invention provides a method for preparing 4'-chloro-2-nitrobiphenyl. The method comprises the following steps: o-chloronitrobenzene and p-chloro potassium benzyltrifluoroborate are adopted as raw materials which are added with a phase transfer catalyst and a palladium catalyst; and the 4'-chloro-2-nitrobiphenyl is obtained through reactions in an aqueous solution under a heating condition, wherein the reactions are carried out under a weak-base condition. The preparation method provided by the invention has the advantages of simplicity in operation, easily available raw materials, little environmental pollution, high yield, relatively good product quality and the like.

Description

Technical field [0001] The invention belongs to the technical field of preparation of chemical raw materials, and particularly relates to a preparation method of boscalid intermediate 4'-chloro-2-nitrobiphenyl. Background technique [0002] Chinese patent CN201310487320.X discloses that 4'-chloro-2-nitrobiphenyl is reduced to nitro group to obtain 4'-chloro-2-aminobiphenyl, and then reacted with 2-chloronicotinyl chloride to obtain the bactericide boscalid Bacteryl. Therefore, 4'-chloro-2-nitrobiphenyl is an important intermediate of the new nicotinamide fungicide boscalid, and the study of its preparation method is more important. [0003] The preparation method of 4'-chloro-2-nitrobiphenyl has the following reports: [0004] 1) Chinese patent CN201410711705.4 mentions that p-halophenylboronic acid or halogenated diphenylboronic acid and o-halonitrobenzene react under heating in a solvent to obtain 4'-chloro-2-nitrobiphenyl. Choose bromine or chlorinate; although the cost is low,...

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Problems solved by technology

[0004] 1) Chinese patent CN201410711705.4 mentions that p-halophenylboronic acid or halogenated diphenylboronic acid and o-halogennitrobenzene react under heating conditions in a solvent to obtain 4'-chloro-2-nitrobiphenyl. In the reaction, only Select bromide or chloride; although the cost is low, the yield is also low at the same time, the reaction is easy to generate self-coupling products, and separation is difficult

[0005] 2) Goossen, LukasJ. et al. (Goossen, LukasJ. etal. Advanced Synthesis & Catalysis, 2009, 351 (16), 2667-2674; Goossen, LukasJ. etal. Chemistry-A European Journal. 2009, 15 (37), 9336-9349) studied A series of potassium o-nitrobenzoate and p-halochlorobenzene in cuprous iodide with a palladium compound as a catalyst, in N-methylpyrrolidone or its mixed solvent with phenanthroline, obtained by reacting at high temperature; in the reaction In the case of high temperature, there are more by-products, and special reagents are not easy to purchase, and the cost is high

[0006] 3) Caron Laurence et al. (Caron, Laurence etal. Organic Letters. 200810 (20), 4533-4536) reported that nitrobenzene, p-chlorobromobenzene and tert-butanol were obtained by the reaction at 125°C under the catalysis of palladium acetate in mesitylene, but its The yield is only 50%; the reaction method not only has a low yield, but also has many impurities and is difficult to separate;

Although the reaction time is short, the reaction under microwave conditions is not suitable for industrial production

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