Reference of 176969-34-9, A common heterocyclic compound, 176969-34-9, name is 3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid, molecular formula is C6H6F2N2O2, its 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.
General procedure: Under nitrogen atmosphere, carboxylic acid II (3mmol), EDCI (3.3 mmol), HOBT (3.3 mmol)and Et3N (1.8 mmol) were placed in a three-necked flask with 40 mL CH2Cl2, and stirred for 2 hat 0 C; then, compound I (2.4 mmol) was added to the flask and allowed to react for 3 h at 0 C.The reaction was monitored by thin-layer chromatography (TLC) (all reactions could be completed in3 h) and, on completion of the reaction, the mixture was washed with saturated NaHCO3 solutionand water, respectively. Then, it was dried over anhydrous Na2SO4, filtered and evaporated onrotavapor in vacuum. Subsequently, crude products III-1-III-18 were purified by silica gel columnchromatography [V (CH2Cl2): V (EA) = 3:1] and crude products III-19-III-36 were purified by silicagel column chromatography [V (PE): V (EA) = 3:1]. Finally, products were recrystallized with thedichloromethane/petroleum ether to obtain pure target compounds.
The synthetic route of 176969-34-9 has been constantly updated, and we look forward to future research findings.
Reference:
Article; Zhang, Shen; Meng, Siqi; Xie, Yong; Yang, Yonggui; Zhang, Yumeng; He, Lu; Wang, Kai; Qi, Zhiqiu; Ji, Mingshan; Qin, Peiwen; Li, Xinghai; Molecules; vol. 24; 14; (2019);,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics