An efficient synthesis of 2,4′-bi-1,3-oxa(thia)zoles as scaffolds for bioactive products (original) (raw)

Synthesis and Biological Evaluation of Bisthiazoles and Polythiazoles

Molecules (Basel, Switzerland), 2018

Small heterocyclic compounds containing nitrogen and sulfur atoms, such as thiazole derivatives, represent a significant class of organic azoles that exhibit promising bioactivities and have a great potential in medicinal and agricultural fields. A convenient and high-yielding synthetic approach for a range of organic molecules is presented. The nuclease-like activities of compounds were studied with the aid of AB1157 DNA and agarose gel electrophoresis. The antioxidant evaluation of the compounds was carried out with different antioxidant techniques, such as ABTS and NO scavenging efficiency. The antibacterial behavior was evaluated against various bacterial strains, both Gram-positive and -negative, and the minimum inhibitory concentration (MIC) values of these compounds were determined. The antiproliferative activities and IC values of the synthesized organic molecules compounds against HEPG-2, MCF-7, and HCT-116 cell lines were evaluated.

Synthesis and characterization of mono- and bicyclic heterocyclic derivatives containing 1,2,4-triazole, 1,3,4-thia-, and -oxadiazole rings

Monatshefte für Chemie - Chemical Monthly, 2008

A series of new N-and S-substituted 1,3,4-oxadiazole derivatives were synthesized. 5-Pyridin-3-yl-3-[2-(5-thioxo-4,5-dihydro-l,3,4-thiadiazol-2-yl)ethyl]-1,3,4-oxadiazole-2(3H)-thione and 5-[(5-(pyridin-3-yl)-1,3,4-oxadiazol-2-ylthio)methyl]-Nphenyl-1,3,4-thiadiazol-2-amine were formed by cyclization of 3-(5-pyridin-3-yl-2-thioxo-1,3,4-oxadiazol-3(2H)-ylpropanimidohydrazide and 2-[(5-pyridin-3-yl-1,3,4-oxadiazol-2-yl)thio]thiosemicarbazide with CS 2 and H 2 SO 4 . On the other hand, a number of new bicyclic 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole derivatives were synthesized. 6-Pyridin-3-ylbis[1,2,4]triazolo[3,4-b:4 0 ,3 0 -d][1,3,4]thiadiazole-3(2H)-thione was synthesized by reaction of 6-(hydrazino)-3-pyridine-3-yl[1,2,4]triazolo [3,4-b][1,3,4]thiadiazole with CS 2 =KOH=EtOH. The structures of the newly synthesized compounds were elucidated by the spectral and analytical data IR, Mass, and 1 H NMR spectra.

Bis (2-Cyanoacetohydrazide) as Precursors for Synthesis of Novel Azoles / Azines and their Biological Evaluation

The present work deals with the synthesis of 2-cyano-N'-(3-(2-(2-cyanoacetyl) hydrazinyl) cyclohex-2-en-1-ylidene) acetohydrazide 3 that used as a key precursor in the manufacture of new heterocyclic derivatives, such as pyrazole, pyrane, pyridine and pyrole incorporating cyclohexene moiety via its reaction with a variety of nucleophilic and electrophilic reagents. The newly synthesized compounds were characterized by their elemental analyses (IR, 1H-NMR, 13C-NMR and Mass spectra) and assessed for their anti-microbial activity.

Synthesis and in Vitro Biological Activities of 4,5-Disubstituted 1,2,4-Triazole-3-Thiols

Advances in Microbiology, 2013

The triazole nucleus is an important part of the therapeutically interesting drug candidate as antimicrobial, analgesic, anticancer, anticonvulsant and anti-inflammatory agents. Methods: Therefore, in this study, twelve 4,5-disubstituted-1,2,4-triazole-3-thiols were synthesized by the reaction of substituted isothiocyanates and hydrazides using the common method of base catalysed intramolecular dehydrative cyclization of substituted thiosemicarbazides 3(a-f) and 4(a-f). The structures of these compounds were characterized by means of FT-IR, 1 H-NMR, and elemental analysis data. All these compounds were screened for antibacterial, antioxidant, antitumor and cytotoxic activities. Results: Among these compounds: 5c, 5f and 6f were found active against gram positive cocci, the compounds 5a, 5b, 5d, 6a and 6f showed 85% free radical scavenging effect at 3 ppm when tested for antioxidant activity, 75% tumors inhibition was recorded using 5c, 5d and 6a and brine shrimps lethality assay declared 5a, 5b and 6d was 129.62 µg/ml, 161.577 µg/ml and 81.56 µg/ml respectively. Conclusion: Compounds carrying significant bioactivity can be further studied using animal models to establish their safety profile prior to initiating clinical trials.

Synthesis of New 1,2,4-Triazole Derivatives with Expected Biological Activities

Synthesis of New 1,2,4-Triazole Derivatives with Expected Biological Activities, 2021

To further study novel N-aceyl, N-thiourea and imidazole derivatives were synthesized. We used a multi-step reaction protocol that began with symmetrical 4-amino- 1,2,4-Triazole [I]. The new Schiff base [II] was derived by condensation of compound [I] with 4-aminoacetophenone in Ethanol and some drops from glacial acetic acid as a catalyst, whereas the Schiff base [III] was synthesized by reacting compound [II] with 4-hydroxyacetophenone in ethanol. N- acyl derivative [IV] was prepared by addition reaction of acetyl chloride to azomethine group of Schiff base [III] in dry benzene. Then, N-thiourea derivative [V] was prepared from reaction of thiourea with N-aceyl derivative [IV] in alkaline solution. The third step involved cyclization reaction of derivative [V] with 2-hydroxy-1,2-diphenylethan-1-one in dimethyl formamide (DMF) to obtain new imidazole derivative [VI]. The synthesized compounds were characterized on the spectroscopic data and their physical properties. Also, we stud...

A fascinating decade for the synthesis of 1,2-azoles

Heterocyclic Communications, 2013

1,2-Azoles comprising pyrazoles, isoxazoles, and isothiazoles have occupied a distinctive position in the design and synthesis of novel biologically active compounds that exert remarkable pharmaceutical activities as medicines and agrochemicals. As a consequence, there has been an increasing interest among synthetic organic/ medicinal chemists in the development of methodologies for the rapid access to these heterocycles. In this review, we have summarized the most significant advances in the construction of functionalized pyrazoles, isoxazoles, and isothiazoles reported in the literature up to 2012.

Synthesis, antibacterial activity of 2,4-disubstituted oxazoles and thiazoles as bioisosteres

Letters in Drug Design and Discovery, 2009

Two series of 2-substituted aryl, heteroaryl and alkyl, 4-substituted aryl 1,3-oxazole (2a-k) and thiazole (4a-k) molecular scaffolds containing divalent bioisosteres, viz., oxygen and sulphur were synthesized by condensing substituted amides and thioamides with substituted phenacyl bromide in absolute ethanol medium. The structure of newly synthesized compounds was characterized by analytical and spectral (IR, 1 H-NMR, 13 C-NMR and LC-MS) methods. The synthesized compounds were evaluated for qualitative (zone of inhibition) and quantitative antibacterial activity (MIC) by agar cup plate and micro-titration methods, respectively. Preliminary pharmacological observations revealed that some of the substituents such as 2-alkyl and heteroaryl at second position, chloro and bromo at the fourth position of the aryl moiety and a divalent sulphur atom in the five-membered heterocyclic ring system influenced significantly the antibacterial activity when compared to its bioisostere counterpart 2-substituted aryl, heteroaryl and alkyl, 4-substituted aryl 1,3-oxazole systems.