Chickpea Leaf Exudates: A Highly Efficient Natural Brønsted Acidic Medium for the Synthesis of Pyran-annulated Heterocycles

: We reported Chickpea leaf exudates (CLE) as a Brønsted acid type naturally available biodegradable, ecofriendly and reusable reaction medium for highly efficient and facile one-pot synthesis of pyran annulated heterocyclic systems like 7-aryl-benzopyrano[4,3-b]benzopyran-6,8-diones, tetrahydrobenzo[b]pyran and dihydropyrano[c]chromenes scaffolds. The analogous products were obtained via tandem Knoevengel-Michael addition and cyclocondensation reaction in ethanol at room temperature with 90-96 % yields in a short reaction time. Moreover, the reaction media containing Bronsted acids can be easily recovered and reused upto five times with a slight decrease in product yields.

Synthesis, Molecular Docking Studies and In Silico ADMET Screening of New Heterocycles Linked Thiazole Conjugates as Potent Anti-Hepatic Cancer Agents

Thiazoles are important scaffolds in organic chemistry. Biosynthesis of thiazoles is considered to be an excellent target for the design of novel classes of therapeutic agents. In this study, a new series of 2-ethylidenehydrazono-5-arylazothiazoles 5a–d and 2-ethylidenehydrazono-5-arylazo- thiazolones 8a–d were synthesized via the cyclocondensation reaction of the appropriate hydrazonyl halides 4a–d and 7a–d with ethylidene thiosemicarbazide 3, respectively. Furthermore, the thiosemicarbazide derivative 3 was reacted with different bromoacetyl compounds 10–12 to afford the respective thiazole derivatives 13–15. Chemical composition of the novel derivatives was established on bases of their spectral data (FTIR, 1H-NMR, 13C-NMR and mass spectrometry) and microanalytical data. The newly synthesized derivatives were screened for their in vitro anti-hepatic cancer potency using an MTT assay. Moreover, an in silico technique was used to assess the interaction modes of the compounds with the active site of Rho6 protein. The docking studies of the target Rho6 with the newly synthesized fourteen compounds showed good docking scores with acceptable binding interactions. The presented results revealed that the newly synthesized compounds exhibited promising inhibition activity against hepatic cancer cell lines (HepG2).

Complementary and Regioselective Synthesis of Isomeric 3-[Isoxazol-3(or 5)-yl]indoles from β-Ethylthio-β-indolyl-α,β-unsaturated Ketones

A simple and efficient method for the complementary and regioselective synthesis of isomeric 3-(isoxazol-5-yl)indoles and 3-(isoxazol-3-yl)indoles has been developed by the regioselective cyclocondensation reaction of β-ethylthio-β-indolyl-α,β-unsaturated ketones and hydroxylamine hydrochloride. It was found that the cyclocondensation reaction in the presence of excess NaOEt in refluxing EtOH gives 3-(isoxazol-5-yl)indoles in good yields, whereas using NaOAc in boiling AcOH gives 3-(isoxazol-3-yl)indoles in good yields.

Synthesis, Characterization and In-Silico Analysis of New 2-Pyrazolines

Heterocyclic compounds such as pyrazolines, pyrimidines, oxazole and isoxazole exhibit different pharmacological activities. The current study involves synthesis of new 2-pyrazolines. The synthesis involves the cyclocondensation reaction of substituted chalcones with (4-fluorophenylthio)acetic acid hydrazide (FTAH) under reflux. The chalcones (C1-C7 / 1a-1g) were synthesized from the reaction of substituted acetophenone with substituted benzaldehyde and FTAH was prepared from 4-fluro thiophenol. New 2-pyrazolines were obtained in good yields (60-70 %). All the compounds were characterized by FT-IR, 1H, 13C NMR and mass spectra. PASS analysis was carried out for the 2-pyrazolines synthesized (P1-P7 / 3a-3g).

Synthesis and Biological Screening of Novel 5-(5-Aryl-1-phenyl-1H-pyrazol-3-yl)-3-aryl-1,2,4-oxadiazole Derivatives

A new series of 5-(5-aryl-1-phenyl-1H-pyrazol-3-yl)-3-aryl-1,2,4-oxadiazole (6a-o) have been synthesized by a cyclocondensation reaction of ethyl 5-(4-chlorophenyl)-1-phenyl-1H-pyrazole-3- carboxylate (3a-c) with aryl imidoxime (5a-e). The newly synthesized pyrazolyl-1,2,4-oxadiazole (6a-o) derivatives were characterized by spectroscopic techniques and screened for in vitro antibacterial activity against Bacillus subtilis (NCIM 2063), Staphylococcus albus (NCIM 2178), Escherichia coli (NCIM 2574), Proteus mirabilis (NCIM 2388) and in vitro antifungal activity against Aspergillus niger (ATCC 504) Candida albicans (NCIM 3100).

A Green, Scalable, and Catalyst-Free One-Minute Synthesis of Quinoxalines

A highly efficient and catalyst-free protocol is reported for the synthesis of quinoxalines via the classical cyclocondensation reaction between aryldiamines and dicarbonyl compounds. Remarkably simple and green reaction conditions employing methanol as solvent afforded medium to excellent yield of quinoxalines after only one-minute reaction time at ambient temperature. The conditions allow at least 10 gram scale synthesis of quinoxalines and should be a preferred starting point for optimization and method of choice for applications in the synthetic community.

Grindstone Chemistry: Design, One-Pot Synthesis, and Promising Anticancer Activity of Spiro[acridine-9,2′-indoline]-1,3,8-trione Derivatives against the MCF-7 Cancer Cell Line

In this study, the synthesis of one-pot 10-phenyl-3,4,6,7-tetrahydro-1H-spiro [acridine-9,2′-indoline]-1,3,8-trione derivatives was achieved via a four-component cyclocondensation reaction, which was carried out in solvent-free conditions, and using p-toluenesulfonic acid (p-TSA) as a catalyst. The product was confirmed by FT-IR, 1H-NMR, 13C-NMR, mass spectra, and elemental analysis. Furthermore, the anticancer activity was screened for all compounds. Among these compounds, compound 1c was more effective (GI50 0.01 µm) against MCF-7 cancer cell lines than standard and other compounds. Therefore, the objective of this study was achieved with a few promising molecules having been demonstrated to be potential anticancer agents.