These common heterocyclic compound, 1310350-99-2, name is 4-Chloro-1-(difluoromethyl)-1H-pyrazole-3-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. Safety of 4-Chloro-1-(difluoromethyl)-1H-pyrazole-3-carboxylic acid
4-Chloro-l -(difluoromethyl)- 1 H-pyrazole-3 -carboxylic acid (0.083 g, 0.423 mmol) was added to DMTMM (0.117 g, 0.423 mmol) in MeOH (2 mL). After stirring the mixture for 5 minutes, a solution of intermediate 1-12 (0.1 g, 0.384 mmol) in MeOH (2 mL) was added at 0 C, and the mixture was stirred for 24 hours. The solvent was evaporated in vacuo. The residue was then suspended in DCM and treated with sat. aq. Na2C03 sol. The organic layer was separated, dried (MgS04), filtered and the solvents evaporated in vacuo. The crude product was purified by flash column chromatography (silica gel; 7 M ammonia in MeOH/DCM 0/100 to 5/95). The desired fractions were collected and concentrated in vacuo. The product was purified further by preparative HPLC (RP, C18 XBridge 30×100 5 urn), mobile phase (gradient 90% 0.1% to 0% 0.1% NH4HCO3/NH4OH pH 9 solution in water, 10% MeCN). The desired fractions were collected and the product was extracted with DCM. The organic layer was separated, dried (MgS04), filtered and concentrated in vacuo. The residue was dried overnight (vacuum oven, 50C) yielding compound 5 (53 mg, 31% yield) as a pale yellow solid.
The synthetic route of 4-Chloro-1-(difluoromethyl)-1H-pyrazole-3-carboxylic acid has been constantly updated, and we look forward to future research findings.
Reference:
Patent; JANSSEN PHARMACEUTICA NV; OEHLRICH, Daniel; GIJSEN, Henricus, Jacobus, Maria; WO2014/198854; (2014); A1;,
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