Synthetic Route of 37687-24-4, These common heterocyclic compound, 37687-24-4, name is Diethyl 3,5-pyrazoledicarboxylate, 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.
To a solution of diethyl 1H-pyrazole-3,5-dicarboxylate (20.0 g, 94.2 mmol) in acetic acid (360 ml) was added dropwise sodium hypochlorite solution (220 ml, 9% in water). After stirring for 6 h at room temperature, the reaction mixture was concentrated under reduced pressure to remove acetic acid, and the remaining mixture was diluted with water (1000 ml). 1.0 M hydrochloric acid was added until pH 4 was reached, and the mixture was extracted with ethyl acetate (3 x 700 ml). The combined organic layers were washed with water and brine, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. Purification of the residue by flash- chromatography on silica gel (eluent: ethyl acetate/petroleum ether 1 :1) afforded the title compound. Yield: 20.0 g (76% of theory, 88% purity). 1H-NMR (300 MHz, DMSO-d6): d [ppm] = 14.93 (br. s, 1H), 4.43-4.30 (m, 4H), 1.39-1.30 (m, 6H).
Statistics shows that Diethyl 3,5-pyrazoledicarboxylate is playing an increasingly important role. we look forward to future research findings about 37687-24-4.
Reference:
Patent; BAYER AKTIENGESELLSCHAFT; BAYER PHARMA AKTIENGESELLSCHAFT; MUeLLER, Steffen; SCHOHE-LOOP, Rudolf; ORTEGA, HERNANDEZ, Nuria; SUeSSMEIER, Frank; JIMENEZ NUNEZ, Eloisa; BRUMBY, Thomas; LINDNER, Niels; GERDES, Christoph; POOK, Elisabeth; BUCHMUeLLER, Anja; GAUGAZ, Fabienne, Zdenka; LANG, Dieter; ZIMMERMANN, Stefanie; EHRMANN, Alexander, Helmut, Michael; GERISCH, Michael; LEHMANN, Lutz; TIMMERMANN, Andreas; SCHAeFER, Martina; SCHMIDT, Georg; SCHLEMMER, Karl-Heinz; FOLLMANN, Markus; KERSTEN, Elisabeth; WANG, Vivian; GAO, Xiang; WANG, Yafeng; (801 pag.)WO2019/219517; (2019); A1;,
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