These common heterocyclic compound, 105434-90-0, name is Ethyl 5-amino-1H-pyrazole-3-carboxylate, 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. Formula: C6H9N3O2
Ethyl 5-amino-1H-pyrazole-3-carboxylate (1.55 g, 10 mmol), tert-butyl acetoacetate (1.65 mL, 10 mmol), 3-fluoro-(4-trifluoromethyl)benzaldehyde (1.92 g, 10 mmol) and sodium bicarbonate (2.52 g, 30 mmol) were heated at 70 C. in DMF (3 mL) overnight. The reaction mixture was allowed to cool then partitioned between ethyl acetate (30 mL) and water (30 mL). The aqueous layer was further extracted with ethyl acetate (20 mL) and the combined organics were dried by passing through a hydrophobic fit, and evaporated to give an orange oil. The residue was dissolved in a minimum amount of DCM and loaded onto a 50 g Si cartridge. The product was eluted with 0-50% ethyl acetate in cyclohexane. The fractions containing the desired product were combined and evaporated to give a pale yellow solid. The solid was triturated with ethyl acetate/cyclohexane to give a white solid (1.25 g). LCMS (Method 3): Rt=1.36 min, m/z 470.5 [M+H]+
The synthetic route of Ethyl 5-amino-1H-pyrazole-3-carboxylate has been constantly updated, and we look forward to future research findings.
Reference:
Patent; CHIESI FARMACEUTISI S.p.A.; Accetta, Alessandro; Rancati, Fabio; Capelli, Anna Maria; Clark, David Edward; Tisselli, Patrizia; Edwards, Christine; Bhalay, Gurdip; (97 pag.)US2018/170939; (2018); A1;,
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