Search results for "4-OXADIAZOLE"
showing 10 items of 65 documents
Unexpected Substituent Effects in the Iso-Heterocyclic Boulton-Katritzky Rearrangement of 3-Aroylamino-5-methyl-1,2,4-oxadiazoles: A Mechanistic Stud…
2019
The kinetics of the iso-heterocyclic mononuclear rearrangement of some 3-aroylamino-5-methyl-1,2,4-ozadiazoles was carefully examined under largely variable acidic or alkaline conditions. This reaction may proceed via two different mechanistic pathways (an uncatalyzed and a base-catalyzed one), as accounted for also by the evaluation of the relevant activation parameters. Substituent effects, as quantified by means of the Hammett’s equation, appear relatively modest; however, they reveal some interesting anomalies, which enabled us to draw a very precise picture of the intimate reaction course.
Investigation on Quantitative Structure-Activity Relationships of 1,3,4-Oxadiazole Derivatives as Potential Telomerase Inhibitors.
2020
Background:Telomerase, a reverse transcriptase, maintains telomere and chromosomes integrity of dividing cells, while it is inactivated in most somatic cells. In tumor cells, telomerase is highly activated, and works in order to maintain the length of telomeres causing immortality, hence it could be considered as a potential marker to tumorigenesis.A series of 1,3,4-oxadiazole derivatives showed significant broad-spectrum anticancer activity against different cell lines, and demonstrated telomerase inhibition.Methods:This series of 24 N-benzylidene-2-((5-(pyridine-4-yl)-1,3,4-oxadiazol-2yl)thio)acetohydrazide derivatives as telomerase inhibitors has been considered to carry out QSAR studies…
CCDC 915397: Experimental Crystal Structure Determination
2013
Related Article: M.Saccone,G.Cavallo,P.Metrangolo,A.Pace,I.Pibiri,T.Pilati,G.Resnati,G.Terraneo|2013|CrystEngComm|15|3102|doi:10.1039/C3CE40268A
The synthesis of fluorinated heteroaromatic compounds. Part 1. Five-membered rings with more than two heteroatoms. A review
2005
(2005). THE SYNTHESIS OF FLUORINATED HETEROAROMATIC COMPOUNDS. PART 1. FIVE-MEMBERED RINGS WITH MORE THAN TWO HETEROATOMS. A REVIEW. Organic Preparations and Procedures International: Vol. 37, No. 5, pp. 447-506.
CCDC 827086: Experimental Crystal Structure Determination
2011
Related Article: A.Kudelko, W.Zielinski, K.Ejsmont|2011|Tetrahedron|67|7838|doi:10.1016/j.tet.2011.07.047
CCDC 780779: Experimental Crystal Structure Determination
2013
Related Article: F.Emmerling, I.Orgzall, B.Dietzel, B.Schulz, J.Larrucea|2012|J.Mol.Struct.|1030|209|doi:10.1016/j.molstruc.2012.04.040
CCDC 780778: Experimental Crystal Structure Determination
2013
Related Article: F.Emmerling, I.Orgzall, B.Dietzel, B.Schulz, J.Larrucea|2012|J.Mol.Struct.|1030|209|doi:10.1016/j.molstruc.2012.04.040
Theoretical study of photoinduced ring-isomerization in the 1,2,4-oxadiazole series
2004
Abstract A theoretical study of photoinduced ring-isomerization of 3-amino-5-methyl- and 3-amino-5-phenyl-1,2,4-oxadiazoles is reported. The results well agree with the reported experimental data: in particular, they explain the ring-photoisomerization into the corresponding 2-amino-1,3,4-oxadiazoles through a ring contraction-ring expansion route; moreover, the occurrence of competing pathways involving both the ring contraction and the internal cyclization–isomerization mechanism during irradiation of the 5-alkyl substituted substrates in the presence of a base has been also substantiated.
Experimental and DFT studies on competitive heterocyclic rearrangements. part 2: A one-atom side-chain versus the classic three-atom side-chain (Boul…
2007
The experimental investigation of the base-catalyzed rearrangements of 3-acylamino-1,2,4-oxadiazoles evidenced a new reaction pathway which competes with the well-known ring-degenerate Boulton- Katritzky rearrangement (BKR). The new reaction consists of a one-atom side-chain rearrangement that is base-activated, occurs at a higher temperature than the BKR, and irreversibly leads to the corresponding 2-acylamino-1,3,4-oxadiazoles. An extensive DFT study is reported to elucidate the proposed reaction mechanism and to compare the three possible inherent routes: (i) the reversible three-atom side-chain ring-degenerate BKR, (ii) the ring contraction-ring expansion route (RCRE), and (iii) the one…
SYNTHESIS AND BIOLOGICAL EVALUATION OF NOVEL SMALL MOLECULES AS PROMISING ALTERNATIVE AGENTS TO COUNTERACT DRUG RESISTANCE IN CANCER AND MICROBIAL IN…
2022
Il cancro rimane un grave problema di salute pubblica, rappresentando la seconda principale causa di morte in tutto il mondo. Tra le diverse tipologie di tumori, l'adenocarcinoma duttale pancreatico (PDAC) è una delle forme più letali nell'uomo, a causa della diagnosi tardiva e delle limitate possibilità di trattamento. Pertanto, lo studio di nuove strategie terapeutiche per i pazienti affetti da PDAC è altamente necessario. Allo stesso modo, il mesotelioma rappresenta una malattia rara ma aggressiva, difficile da diagnosticare per il lungo periodo di latenza prima dei segni clinici. Gli approcci terapeutici standard includono la chirurgia, la chemioterapia e la radioterapia. Tuttavia, la s…