<b>Synthesis and Biological Activities of Novel 1,4-Bridged Bis-1,2,4-Triazoles, Bis-1,3,4-Thiadiazoles and Bis-1,3,4-Oxadiazoles</b>

Shaker, Raafat M.; Mahmoud, Alaa F.; Abdel-Latif, F. F.

doi:10.1080/104265090509199

Cited by 45 publications

(26 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such a downfield signal can be assigned only to the thioamide CS carbon atom, which was reported to appear at δC value greater than 169 ppm in related systems [37][38][39][40]. It is worthwhile to report here that the thione form is the stable form in which compound 8 mainly exists since its IR spectrum revealed no absorption band at around ν 2600-2550 cm -1 , which is indicative of the thiol form [35,36,[41][42][43]. In the 1 H NMR spectrum of 8, the absence of a signal due to the SH proton that would be expected to resonate in the range δH 1.6-4.0 ppm [35,37] also provided confirmatory evidence for thione formation.…”

Section: Chemistrymentioning

confidence: 97%

Regioselective synthesis and biological evaluation of some novel thiophene-containing heterocyclic scaffolds as potential chemotherapeutic agents

Gaber

Bagley

2011

Eur. J. Chem.

View full text Add to dashboard Cite

KEYWORDSIn the reaction of 2-amino-3-carbethoxythiophene derivative 2b with hydrazine hydrate the respective aminocarbohydrazide 3 was isolated. Treatment of the latter product with carbon disulfide in alkaline medium caused a heterocyclization to give 1,3,4-oxadiazole-2-thione 5 rather than 3-amino-2-thioxothieno[2,3-d]pyrimidin-4-one 4, which could be obtained on treatment of carbohydrazide 3 with thiourea. The structure of products 4 and 5 was proved by spectroscopic methods and chemical transformations. Derivatization led to two novel series of condensed and uncondensed thiophenes, which were of significant interest for biological study. Since compound 4 contains two adjacent reactive functional groups, it reacted readily with different electrophilic reagents to provide a series of thieno[2,3-d]pyrimidin-4-one derivatives with annelated bridgehead nitrogen heterocycles 8-11, whereas a second series of 3-heteroaryl-substituted thiophenes 13-17 was obtained by thioamide functionalization in 1,3,4-oxadiazole derivative 5 using various chemical reagents. The new thiophene-based derivatives were evaluated for their preliminary antimicrobial activity against a representative panel of Gram-positive and Gram-negative bacteria as well as fungi strains. The compounds tested displayed different levels of inhibitory effects, with the assays carried out on two pathogenic bacteria and two pathogenic fungi. Of these compounds, the monocyclic aminothiophene derivative 15 showed the highest effect on pathogenic bacteria, while the tricyclic condensed thiophene derivative 8 was observed to have the same inhibitory effect against pathogenic mould (Aspergillus flavus) as the reference drug Amphotericin B. For those derivatives belonging to first series of condensed thiophenes with annelated bridgehead nitrogen heterocycles, it has been observed that the antibacterial effect was in general found to be significantly higher than the corresponding uncondensed analogues. Although most of the condensed and uncondensed thiophenes under investigation showed generally remarkable in vitro antibacterial activity, unfortunately, no significant antifungal activity was observed with any of the compounds tested except for 8. Surprisingly, compound 8 displayed an excellent effect on fungus (A. flavus) on the one hand, whereas the lowest effect on bacteria on the other. The attachment of a triazolothiadiazine moiety to a thiophene ring could be considered as a promising strategy for the development of new therapeutic antibacterial agents related to the aminothiophene system. Thienopyrimidinone Cyclocondensation Cyclodesulfurization Hydrazinolysis Alkylation Antimicrobial activity

show abstract

Section: Chemistrymentioning

confidence: 97%

Regioselective synthesis and biological evaluation of some novel thiophene-containing heterocyclic scaffolds as potential chemotherapeutic agents

Gaber

Bagley

2011

Eur. J. Chem.

View full text Add to dashboard Cite

show abstract

“…Shaker et al 61 reported that the bis-semicarbazide 92 on treatment with NaOH underwent cyclization to the corresponding 5,5′-(1,4-phenylene)bis(1,3,4-oxadiazol) 125 (Scheme 40).…”

Section: Scheme 39mentioning

confidence: 99%

“…Shaker et al 61 reported that the treatment of 1,4-phenylene-bis-thiosemicarbazide 97 with sodium hydroxide gives 3,3′-(1,4-phenylene)bis(1H-1,2,4-triazole-5(4H)-thione) 98 (Scheme 27).…”

Section: Figure 11mentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of 1,4-phenylene bridged bis-heterocyclic compounds

Shaker¹

2011

Arkivoc

View full text Add to dashboard Cite

show abstract

“…15 Furthermore, 1,3-thiazines are an important type of heterocycles showing a wide variety of pharmacological properties. [16][17][18][19][20] Prompted by the aforesaid biological and pharmaceutical activities, and as a part of our continuing interest on the synthesis of new polyfunctionally substituted heterocyclic [21][22][23][24][25][26][27][28][29][30] and spiro heterocyclic compounds [31][32][33][34] of expected biological activity, we now report the versatile and hitherto unreported synthesis of 1-thia-5,9-diazaspiro [5.5]undec-2-ene, and its base-catalyzed recyclization to 1,5,9-triaza-spiro [5.5]undec-2-ene and spiro(piperidine-4,2'-thieno [2,3-d]pyrimidine) derivatives with the purpose of investigating in the future their possible biological activity. Scheme 1 outlines the synthesis of the ethyl ester of 3-cyano-4-oxo-2-phenylamino-1-thia-5,9-diaza-spiro [5.5]undec-2-ene-9-carboxylic acid 3a,b from the cyclocondensation of 2-cyano-3-mercapto-3-phenylamino-acrylamide 1 with ethyl 4-oxo-piperidine-1-carboxylate 2a and/or 1-benzylpiperidin-4-one 2b in the presence of catalytic amounts of p-toluenesulfonic acid (p-TSA) in boiling ethanol.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of novel 1-thia-5,9-diaza-spiro[5.5]undec-2-ene and its recyclization to 1,5,9-triaza-spiro[5.5]undec-2-ene and/or spiro(piperidine-4,2’-thieno[2,3-d]pyrimidine)

Shaker¹,

Ibrahim²,

Abdel-Latif³

et al. 2010

Arkivoc

View full text Add to dashboard Cite

show abstract

Synthesis and Biological Activities of Novel 1,4-Bridged Bis-1,2,4-Triazoles, Bis-1,3,4-Thiadiazoles and Bis-1,3,4-Oxadiazoles

Cited by 45 publications

References 17 publications

Regioselective synthesis and biological evaluation of some novel thiophene-containing heterocyclic scaffolds as potential chemotherapeutic agents

Regioselective synthesis and biological evaluation of some novel thiophene-containing heterocyclic scaffolds as potential chemotherapeutic agents

Synthesis of 1,4-phenylene bridged bis-heterocyclic compounds

Synthesis of novel 1-thia-5,9-diaza-spiro[5.5]undec-2-ene and its recyclization to 1,5,9-triaza-spiro[5.5]undec-2-ene and/or spiro(piperidine-4,2’-thieno[2,3-d]pyrimidine)

Contact Info

Product

Resources

About