1,2,4-triazole and its preparation method

Abstract

The invention discloses 1,2,4-triazole and a preparation method thereof. The 1,2,4-triazole is prepared by taking aryl diazonium fluoborate, a diazo ester derivative and organic nitrile as reaction substrates, taking transition metal as a catalyst and taking inorganic alkali as an additive through cyclization reaction. The method has the following characteristics: the reaction is more economic, the substrate universality is higher, late functionalization is realized easily, the reaction condition is mile, the reaction can be carried out in air, the use amount of the catalyst is small, aftertreatment is simple and convenient, and purification and industrialized application of products are facilitated. Meanwhile, the raw materials such as the reactants and the catalyst are cheap and easily available, the reaction composition is reasonable, ligand is not needed, the reaction steps are few, high yield can be obtained only by one-step reaction, the requirement and the direction of the contemporary green chemistry and medicine chemistry are met, and the preparation method is suitable for screening high-activity 1,2,4-triazole medicines.

Description

technical field [0001] The invention relates to 1,2,4-triazole and a preparation method thereof, belonging to the technical field of organic synthesis. Background technique [0002] 1,2,4-Triazole, as a very valuable five-membered nitrogen-containing heterocyclic skeleton, widely exists in many functional molecules and is used in organic catalysis, materials science and other fields. In addition, the 1,2,4-triazole skeleton also appears in many biologically active molecules, and has important uses in the pharmaceutical industry and pesticides. At present, the methods for preparing 1,2,4-triazoles have disadvantages such as many reaction steps, complicated preparation of raw materials, complex reaction conditions, and narrow substrate scope. E.g: [0003] (1) Michael J. Stocks et al reported the preparation of 1,2,4-triazole from primary amines, amide diacetal derivatives, and hydrazide derivatives, but multi-step reactions are required and the scope of reaction substrates ...

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Problems solved by technology

[0003] (1) Michael J. Stocks et al reported the preparation of 1,2,4-triazole from primary amines, amide diacetal derivatives, and hydrazide derivatives, but multi-step reactions are required and the scope of reaction substrates is narrow (see: Michael J. Stocks; Org. Lett. 2004, 6 , 2969);

[0004] (2) Hideko Nagasawa et al. reported the preparation of 1,2,4-triazole from amidine hydrochloride derivatives and organic nitriles, but the reaction temperature was high and the substrate range was narrow (see: Hideko Nagasawa; J. Am. Chem. Soc. 2009, 131 ,15080);

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