Organotellurium Chemistry: Synthesis and Properties of 2-Acylamino- and 2-Arylamino-1,3-benzotellurazoles
Whitney Elisabeth Smith,
Donna Victoria Franklin,
Kourtni Lynn Goutierrez,
Frank Robert Fronczek,
Franz Andreas Mautner,
Thomas Junk
Issue:
Volume 5, Issue 3, September 2019
Pages:
49-54
Received:
6 December 2018
Accepted:
10 July 2019
Published:
30 July 2019
Abstract: Synthetic methods have been developed to prepare novel 1,3-benzotellurazoles carrying acylamino and arylamino moieties in position 2, in order to investigate their propensity to self-assemble to supramolecular structures. The targeted compounds were obtained in yields ranging from 44% to 67%, by reacting bis(2-aminophenyl) ditelluride with acyl- and aryl isothiocyanates, respectively, and subsequent reductive cyclization of the resulting thiourea derivatives. Seven novel 1,3-benzotellurazole derivatives were prepared: 2-benzoylamino-1,3-benzotellurazole, 2-(4-chlorobenzoylamino)-1,3-benzotellurazole, 2-(2-bromobenzoylamino)-1,3-benzotellurazole, 2-(4-bromobenzoylamino)-1,3-benzotellurazole, 2-(4-methoxybenzoylamino)-1,3-benzotellurazole, 2-phenylamino-1,3-benzotellurazole, and 2-(4-chlorophenylamino-1,3-benzotellurazole. A simplified protocol was employed to synthesize all acyl isothiocyanates needed for their preparation from benzoyl halide derivatives and potassium thiocyanate. The reductive cyclization of the intermediate thioureas was challenging, only the use of hydroxymethanesulfinate in the presence of elemental mercury provided synthetically useful product yields. A mechanism was proposed, consisting of the insertion of mercury into the Te-Te bond, followed by intramolecular nucleophilic attack of the thiocarbonyl moiety by the resulting insertion product. All 2-acylamino-1,3-benzotellurazoles are crystalline solids, which are stable to ambient light, air and moderate heat. A characterization of selected samples by X-ray crystallography indicated that they form dimers in solid state, resulting from hydrogen bonding between the exocyclic and endocyclic nitrogen atoms of two adjacent molecules. This sets them apart from 2-alkyl- and 2-aryl-1,3-benzotellurazoles, which are known to self-assemble into supramolecular wires.
Abstract: Synthetic methods have been developed to prepare novel 1,3-benzotellurazoles carrying acylamino and arylamino moieties in position 2, in order to investigate their propensity to self-assemble to supramolecular structures. The targeted compounds were obtained in yields ranging from 44% to 67%, by reacting bis(2-aminophenyl) ditelluride with acyl- an...
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In vitro Anti Leukemia Cancer Activity of Some Novel Pyrazole Derivatives and Pyrazoles Containing Thiazole Moiety
Amal Mahmoud Youssef Moustafa
Issue:
Volume 5, Issue 3, September 2019
Pages:
55-70
Received:
30 June 2019
Accepted:
1 August 2019
Published:
14 August 2019
Abstract: The design and syntheses of several novel pyrazole derivatives (2, 5, 6 and 7) and pyrazole derivatives (3 and 4) containing thiazole moiety via by ethyl β-(p-chlorophenyl)–α-cyanoacrylate (1) and thiosemicarbazide as starting materials. Pyrazole derivatives (3 and 4) containing thiazole moiety were synthesized via cyclization of pyrazole derivative (2) with bromomethyl arylketones, to give compound 3, followed by acetylation. N- (3- methoxy-2-hydroxybenzal) -3- (p -chlorophenyl)-4- cyano-5-oxopyrazol-1-thiocarboxamide (6) was synthesized via reaction of compound 2 with 3-methoxy-2-hydroxybenzaldehyde. Structures of all compounds were confirmed by elemental analysis, FT-IR, 1H-NMR, 13C-NMR and mass spectrometry. The cytotoxic activity of all the synthetic compounds were evaluated against Leukemia HL-60 compared with Doxorubicicn. The cytotoxic activity was checked in vitro for the recently prepared compounds by using the MTT assay. Compounds 4, 6 and 9 were the most active against Leukemia HL-60. The IC50 values of them were less than 5 µM in the range of 1.35-4.78 µM. In addition, compounds 3 and 5 showed less antiproliferative activity against Leukemia HL-60 cells with IC50 values in the range 5.39-8.82 µM. Compound 6 was the most potent cytotoxic activity. The studies biological activity includes cell cycle analysis, apoptosis detection assay and Topoisomerase II inhibition activity assay explained that compound 6 is a strong Topo II inhibitor.
Abstract: The design and syntheses of several novel pyrazole derivatives (2, 5, 6 and 7) and pyrazole derivatives (3 and 4) containing thiazole moiety via by ethyl β-(p-chlorophenyl)–α-cyanoacrylate (1) and thiosemicarbazide as starting materials. Pyrazole derivatives (3 and 4) containing thiazole moiety were synthesized via cyclization of pyrazole derivativ...
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Green Synthesis and Antibacterial Activity of Pyrido[2,3-e]1,3,4-Oxadiazine Derivatives
Fayez Mohamed Eissa,
Mohamed Selim,
Ahmed Sayed,
Mohamed Sharkawi
Issue:
Volume 5, Issue 3, September 2019
Pages:
71-75
Received:
22 June 2019
Accepted:
13 July 2019
Published:
23 August 2019
Abstract: Pyrido[2,3-e]1,3,4-Oxadiazines heterocyclic ring system and its derivatives were efficiently synthesized via benign and sustainable methodology using Grinding Chemistry as a recognized solvent free, less hazard, and low risk pathway. The course of the reaction was completed by refluxing using ecofriendly and renewable source of initiation energy via means of parabolic solar reflectors. The implemented parabolic solar reflectors employed the direct sunlight as a clean and sustainable source of activation energy to activate the required chemical reaction. The green context of the procedure was evaluated and discussed by comparing its benign components with the non-green components of the conventional one. The green components of the green procedures were found virtually preferred over the conventional one with its simplicity, time efficiency, atom economy, safety, sustainability, low cost, yield optimization, excellent conversion of the reactants and ease of applicability. The biological activity of the prepared compounds was evaluated and discussed against some bacterial strains naming, (Escherichia Coli, Pseudomonas, Serratia and Bacillus Cereus), and was found to display promising anti-bacterial results that encourage future pharmaceutical studies to quantify its potency. All the synthesized compounds were purified using glass column chromatography packed with silica and their structures were identified and confirmed by elemental analysis and Mass spectra, 1HNMR, 13CNMR spectral data.
Abstract: Pyrido[2,3-e]1,3,4-Oxadiazines heterocyclic ring system and its derivatives were efficiently synthesized via benign and sustainable methodology using Grinding Chemistry as a recognized solvent free, less hazard, and low risk pathway. The course of the reaction was completed by refluxing using ecofriendly and renewable source of initiation energy vi...
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