A new strategy for the synthesis of pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]pyrimidines and pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidines

Synthesis and biological evaluation of new pyrazolo[3,4-d]pyrimidine derivatives

“…This rearrangement is consistent with those reported in some earlier reports 14,15 . Therefore, to confirm the structure of compounds 3, an X-ray crystallographic study was carried out of compound 3d obtained by condensation of 2d with aniline ( Figure 1).…”

A Convenient Synthesis of New 3,7-Diphenylthieno[3,2-e]bis[1,2,4] triazolo[4,3-a:4',3'-c]pyrimidine Derivatives by Oxidative Cyclization Using Alumina-supported Calcium Hypochlorite

“…Although the mechanism of cyclization is not certain, it is expected to be similar to the proposed mechanisms of other related oxidative cyclizations of pyrazolopyrimidinyl hydrazones 6 and quinazolinyl hydrazones 13 by ferric chloride or the oxidative cyclizations of thienopyrimidinyl hydrazones 8 by iodobenzene diacetate. The conversion of 11 to 6 was considered to proceed via cyclization of the corresponding nitrilimine intermediates through the electrophilic attack of hypochlorite on 11 followed by elimination of HCl (Scheme 2).…”

“…For instance, thienotriazolopyrimidinone 1 and pyrazolotriazolopyrimidine 2 derivatives of tricyclic heterocyclic compounds as shown in Fig. 1 have been recently synthesized for xanthine oxidase inhibitor 5 and adenosine A2A/A3 receptor antagonists, 6 respectively. The compound 3, 3,9-diphenyl-bis-1,2,4-triazolo [4,3-a][4',3'-c] pyrimidine derivatives, were also found to possess strong antibacterial activity.…”

Synthesis, antimicrobial, antioxidant activities of novel 6-aryl-5-cyano thiouracil derivatives

“…These hydrazino derivatives exerted promising antibacterial, antifungal and anticancer activities [17][18][19]. In addition, the reactions of hydrazino pyrimidines with formic acid, trietylorthoformate(TEOF)and CS 2 (one carbon donor moieties) afforded the corresponding triazolopyrimidines [20][21][22][23][24][25],which are known to exhibit interesting Pharmaceutical activities [26,27]. In the light of the aforementioned facts, and in continuation for our interest in the synthesis of biologically active heterocyclic compounds, we report herein the synthesis and biological evaluation of novel 6-aryl-5-cyano thiouracil derivatives as antimicrobial and antioxidant agents.…”