Application of 175277-11-9,Some common heterocyclic compound, 175277-11-9, name is 3-tert-Butyl-1-methylpyrazole-5-carboxylic Acid, molecular formula is C9H14N2O2, 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.
46) 3-(tert-butyl)-N-(6-fluoro-2,3-dimethoxybenzyl)-1-methyl-1H-pyrazole-5-carboxamide To a solution of aldehyde (250 mg, 1.36 mmol, 1.0 eq) in toluene (15 mL) was added 2,4-dimethoxybenzyl amine (227 mg, 1.36 mmol, 1.0 eq) and the reaction mixture was stirred at room temperature for 24 h. Toluene was removed to give a residue, which was taken in MeOH (15 mL) and then NaBH4 (103 mg, 2.72 mmol, 2.0 eq) was added slowly. The reaction mixture was stirred at room temperature for 6 h. Solvent was removed and the residue was extracted in Ethyl acetate and stirred with saturated aq NaHCO3 for 1 h. The organic layer was collected, dried and solvent was removed to give the crude amine, which was used in the next step without further purification. To a solution of the crude amine (0.45 mmol, 1.1 eq) in DMF (5 mL) were added the acid (75 mg, 0.407 mmol, 1.0 eq), DIEA (262 mg, 2.04 mmol, 5 eq) and HBTU (205 mg, 0.54 mmol, 1.2 eq) and the reaction mixture was stirred at rt for 12 h. The reaction mixture was then diluted with ethyl acetate (20 mL) and washed with 10% aq HCl (1*20 mL), sat NaHCO3 (1*20 mL) and water (4*20 mL). Organic layer was collected, dried (MgSO4) and evaporated to give a crude product, which was purified by column chromatography (EtOAc/Hexane 25% to 75%)) to give the amide, which was directly used in the next step. The amide was treated with 95% TFA:H2O for 12 h. TFA was removed and azeotroped with toluene to give a residue, which was purified by column chromatography (EtOAc/Hexane 10% to 50%) to give the desired product. Mass Spectrum (LCMS, ESI Pos.) Calcd. For C18H25FN3O3: 350.0 (M+H), Found 350.0.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 3-tert-Butyl-1-methylpyrazole-5-carboxylic Acid, its application will become more common.
Reference:
Patent; Prosetta Antiviral ,Inc.; Selvarajah, Suganya; Paulvannan, Kumar; (58 pag.)US2018/118679; (2018); A1;,
Pyrazole – Wikipedia,
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