176969-34-9,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.
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.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid, its application will become more common.