Some common heterocyclic compound, 176969-34-9, name is 3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid, molecular formula is C6H6F2N2O2, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. Formula: C6H6F2N2O2
To a 200 ml single-neck round bottom flask was added 28.39 mmol 3 dissolved in 40 ml of dichloromethane, and then 31.32 mmol of triethylamine was added. Stir for 10 minutes; Further adding 31.23 mmol of EDCI and catalytic amount of DMAP to the reaction. Stir at room temperature for 30 minutes. Finally, 28.39 mmol of N,O-dimethylhydroxylamine hydrochloride was added to the system. Stir at room temperature overnight, after the reaction is completed, The mixture was suction filtered under reduced pressure and the filtrate was concentrated to remove solvent. It was dissolved in 20 ml of dichloromethane and diluted. Wash once with 30 ml of water, separate the aqueous layer and extract twice with dichloromethane (10 ml × 2). The combined organic layers were washed once with 20 ml of saturated sodium chloride solution. The aqueous layer was separated and extracted twice with dichloromethane (10 mL×2). The combined organic layers were dried over anhydrous sodium sulfate; The filtrate is concentrated to remove the solvent.With petroleum ether / ethyl acetate (2:1, volume / volume) purification by column chromatography to give a white solid 6; yield 91%;
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 176969-34-9, its application will become more common.
Reference:
Patent; Nankai University; Fan Zhijin; Yu Bin; Yang Dongyan; Zhao Bin; Guo Xiaofeng; Zhang Nailou; Hao Zesheng; Wu Qifan; Zhou Shuang; Cao Lixin; (36 pag.)CN110128419; (2019); A;,
Pyrazole – Wikipedia,
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