Abstract
The synthesis of 3-methyl-1,4-diphenyl-7-thioxo-4,6,8,9-tetrahydropyrazolo[5,4-b] pyrimidino[5,4-e]pyridine-5-one (6) was achieved by two different one-pot multi-component synthesis (one-pot three-component and one-pot four component synthesis). Mono and dialkylation of 6 under different conditions gave compounds 7–11. The hydrazine 12 produced from reaction of 9 with N2H4 was subjected to reactions with some aromatic aldehydes, ethyl acetoacetate, acetyl acetone, ethyl cyanoacetate and triethyl orthoformate to give 13–17, respectively. Compound 12 upon reaction with CS2, nitrous acid, benzoin, chloroacetone and phenacyl bromide gave 18,20,21,22. Alkylation of 18 with ethyl iodide, ethyl chloroacetate and phenacyl bromide gave 19a–c. The antibacterial and antifungal activities of selected derivatives were evaluated.
Highlights
Multicomponent domino reactions (MDRs), those performed in aqueous media, have become an increasingly useful tool for the synthesis of chemically and biologically important compounds because of their convergence, atom economy, and other suitable characteristics from the point of view of green chemistry [1,2,3,4,5,6,7,8,9,10]
For all the benefits mentioned above and as part of our program investigating syntheses using pyrazole and fused pyrazoles that have biological importance [22,23,24,25,26,27,28,29,30,31,32,33], we report the synthesis of pyrazolo[5,4-b]pyrimidino[5,4-e]pyridinethiones in a one-pot four component environmental friendly method in light of recently reported methods [34,35,36,37]
We first describe a comparison between two methods for the construction of pyrazolo[5,4b]pyrimidino[5,4-e]pyridin-5-one (6), a one-pot four-component domino reaction of phenyl hydrazine
Summary
Multicomponent domino reactions (MDRs), those performed in aqueous media, have become an increasingly useful tool for the synthesis of chemically and biologically important compounds because of their convergence, atom economy, and other suitable characteristics from the point of view of green chemistry [1,2,3,4,5,6,7,8,9,10]. Pyrazolo-annulated heterocycles such as Molecules 2012, 17 pyrazolopyridopyrimidines have attracted considerable interest because their derivatives display a wide range of pharmacological activities, e.g., as anticonvulsants [17], antiproliferative agents [18], anti-inflammatories and analgesic agents [19] In addition these types of compounds are inhibitors of cyclic guanosine-3',5'-monophosphate phosphodiesterase (cGMP PDE), and are thereby agents against erectile dysfunction [20]. For all the benefits mentioned above and as part of our program investigating syntheses using pyrazole and fused pyrazoles that have biological importance [22,23,24,25,26,27,28,29,30,31,32,33], we report the synthesis of pyrazolo[5,4-b]pyrimidino[5,4-e]pyridinethiones in a one-pot four component environmental friendly method in light of recently reported methods [34,35,36,37]
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