Application of 926663-00-5, With the rapid development and complex challenges of chemical substances, the synthesis of new drugs is usually one of the most effective ways to increase yield.926663-00-5, name is Ethyl 5-oxo-4,5-dihydropyrazolo[1,5-a]pyrimidine-3-carboxylate, molecular formula is C9H9N3O3, molecular weight is 207.19, as common compound, the synthetic route is as follows.
B) ethyl 5-chloropyrazolo[1,5-a]pyrimidine-3-carboxylate Ethyl 5-hydroxypyrazolo[1,5-a]pyrimidine-3-carboxylate (18.0 g) was suspended in acetonitrile (40 mL), phosphorus oxychloride (40 mL) was added at room temperature, and the mixture was stirred under a nitrogen atmosphere at 110 C. for 4 hr. The reaction mixture was cooled, and concentrated under reduced pressure. The residue was diluted with ethyl acetate and neutralized with aqueous sodium bicarbonate solution, and insoluble material was filtered off with Celite. The organic layer of the filtrate was purified by a silica gel pad, and the solvent was evaporated under reduced pressure. The precipitated solid was washed with ethyl acetate/diisopropyl ether to give the title compound (14.1 g). The mother liquor was further concentrated under reduced pressure and the resulting solid was washed with ethyl acetate/diisopropyl ether to give the title compound (2.40 g). 1H NMR (300 MHz, CDCl3) delta 1.42 (3H, t, J=7.2 Hz), 4.43 (2H, q, J=7.2 Hz), 6.99 (1H, d, J=7.2 Hz), 8.56 (1H, s), 8.63 (1H, d, J=7.2 Hz).
Statistics shows that 926663-00-5 is playing an increasingly important role. we look forward to future research findings about Ethyl 5-oxo-4,5-dihydropyrazolo[1,5-a]pyrimidine-3-carboxylate.
Reference:
Patent; TAKEDA PHARMACEUTICAL COMPANY LIMITED; Kawasaki, Masanori; Mikami, Satoshi; Nakamura, Shinji; Negoro, Nobuyuki; Ikeda, Shuhei; Nomura, Izumi; Ashizawa, Tomoko; Imaeda, Toshihiro; Seto, Masaki; Sasaki, Shigekazu; Marui, Shogo; Taniguchi, Takahiko; (130 pag.)US2016/159808; (2016); A1;,
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