176969-34-9, These common heterocyclic compound, 176969-34-9, name is 3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid, 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.
1-methyl-3-difluoromethyl-1H-pyrazole-4-carboxylic acid (7.76 g, 40 mmol) represented by formula (III) was refluxed with thionyl chloride (47.6 g, 0.4 mol) for 4 hours. When the reaction system turns to a pale yellow transparent liquid, the reaction is continued for 30 min. The reaction is stopped, and after cooling down to room temperature, 1-methyl-3-difluoromethyl-1H-pyrazole-4-acyl chloride is obtained by distillation under reduced pressure. 1-methyl-3-difluoromethyl-1H-pyrazole-4-carbonyl chloride (2 mmol) was added to 15 ml of dichloromethane, Phenylmethanamine (2.1 mmol) was added followed by slow triethylamine (0.3 g, 3 mmol) stirring overnight at room temperature; followed by TLC (EA:PE=2:1 (V)) until the reaction was complete with dichloromethane. Three times extraction with water=1:1 (V) system, concentration of organic layer, extraction with toluene or 75% ethanol, and column chromatography (EA:PE=2:1(V)) to obtain N-benzyl as shown in (K11). 1-Methyl-3-(difluoromethyl)-1H-pyrazole-4-carboxamide
Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 176969-34-9.