Pyrazolo-pyrido-pyrimidine-diones

Applications of MCR-Derived Heterocycles in Drug Discovery Table 6 Antibacterial activities of select pyrazolo-pyrido-pyrimidine-diones... 

Bazgir A, Khanaposhtani MM, Soorki AA (2008) One-pot synthesis and antibacterial activities of pyrazolo[4, 3 5, 6]pyrido[2, 3-] d pyrimidine-dione derivatives. Bioorg Med Chem Lett 18 5800-5803... 

Ring opening of 3-(phenylsulfonyloxy)pyrido[3,4-d]pyrimidine-2,4-dione (587) with sodium methoxide, followed by a Lossen rearrangement gave the hydrazinopyridine ester (588) which in refluxing acid yielded 1 //-pyrazolo[3,4-c]pyridin-3-one (589) (Scheme 75) <74JHC163>. 

Using the general method described in Section 7.08.10.2 <74JHC163> 3-(phenylsulfonyloxy) pyrido[4,3-fi ]pyrimidine-2,4-dione (590) ring opens with sodium methoxide and rearranges to a hydrazinopyridine ester, which in refluxing acid yields l//-pyrazolo[4,3-c]pyridin-3-one (591) (Equation (59)). 

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