Reference of 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.
Step 7: Production of N-[2-[3-chloro-5-(cyclopropylethynyl)pyridin-2-yl]-2-(isopropoxyimino)ethyl]-3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxamide To a 1 ml solution of 68 mg of 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid in dichloromethane, 10 mg of N,N-dimethylformamide and 66 mg of oxalyl chloride were added. After completion of the addition, the reaction mixture was stirred at room temperature for 1 hour. After completion of the reaction, the solvent was distilled off from the reaction mixture under reduced pressure. The obtained residue was dissolved in 1 ml of dichloromethane and, with stirring under cooling with ice, added dropwisely to a mixed solution of 100 mg of 2-amino-1-[3-chloro-5-(cyclopropylethynyl)pyridin-2-yl]ethanone-O-isopropyl oxime and 200 mg of potassium carbonate in 2 ml of dichloromethane and 2 ml of water. After completion of the dropwise addition, stirring was further continued for 1 hour at room temperature. After completion of the reaction, 10 ml of water was added to the reaction mixture, followed by extraction with dichloromethane (10 ml*1). The obtained organic layer was washed with water (10 ml*1), and then dehydrated and dried by using saturated aqueous sodium chloride and then anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The obtained residue was purified by silica gel column chromatography by eluting it with ethyl acetate-hexane (2:3), to obtain 150 mg of the desired product as a pale yellow resinous substance (E/Z=2/1). 1H NMR (CDCl3, Me4Si, 300 MHz) b 8.45 and 8.43 (d, J=1.8 Hz, 1H), 7.88 and 7.82 (s, 1H), 7.68 and 7.66 (d, J=1.8 Hz, 1H), 7.12 (bs, 1H), 6.85 and 6.75 (t, J=54.2 Hz, 1H), 4.70 and 4.46 (d, J=6.1, 4.9 Hz, 2H), 4.47 and 4.36 (sep, J=6.3 Hz, 1H), 3.90 and 3.87 (s, 3H), 1.4-1.55 (m, 1H), 1.32 and 1.18 (d, J=6.3 Hz, 6H), 0.8-1.0 (m, 4H).
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.