A synthetic route to novel 3-substituted-2,1-benzisoxazoles from 5-(2-nitrobenzylidene)(thio)barbiturates

Metal-free tandem reactions of 2-iodoaryl ynones with sodium azide for the synthesis of benzoisoxazole containing 1,2,3-triazoles

A metal-free approach has been developed for the synthesis of benzo[c]isoxazole (anthranils) containing 1,2,3-triazoles. The reaction proceeded efficiently through a [3 + 2] azide-alkyne cycloaddition, SNAr azidation and denitrogenative cyclization sequence. The metal-free protocol enabled effective construction of one N-O and three C-N bonds in one pot. In addition, the synthetic utility of the current methodology was further demonstrated by late stage modification of the obtained products.

From Xanthine Oxidase Inhibition to In Vivo Hypouricemic Effect: An Integrated Overview of In Vitro and In Vivo Studies with Focus on Natural Molecules and Analogues

Hyperuricemia is characterized by elevated uric acid (UA) levels on blood, which can lead to gout, a common pathology. These high UA levels are associated with increased purine ingestion and metabolization and/or its decreased excretion. In this field, xanthine oxidase (XO), by converting hypoxanthine and xanthine to UA, plays an important role in hyperuricemia control. Based on limitations and adverse effects associated with the use of allopurinol and febuxostat, the most known approved drugs with XO inhibitory effect, the search for new molecules with XO activity is growing. However, despite the high number of studies, it was found that the majority of tested products with relevant XO inhibition were left out, and no further pharmacological evaluation was performed. Thus, in the present review, available information published in the past six years concerning isolated molecules with in vitro XO inhibition complemented with cytotoxicity evaluation as well as other relevant studies, including in vivo hypouricemic effect, and pharmacokinetic/pharmacodynamic profile was compiled. Interestingly, the analysis of data collected demonstrated that molecules from natural sources or their mimetics and semisynthetic derivatives constitute the majority of compounds being explored at the moment by means of in vitro and in vivo animal studies. Therefore, several of these molecules can be useful as lead compounds and some of them can even have the potential to be considered in the future clinical candidates for the treatment of hyperuricemia.

Design, synthesis and evaluation of 5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione-Based fibrates as potential hypolipidemic and hepatoprotective agents

Six novel target compounds 5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione (ADT) based fibrates were synthesized and evaluated. All the synthesized compounds were preliminarily screened by using the Triton WR-1339-induecd hyperlipidemia model, in which T1 exhibited more potent hypolipidemic property than positive drug fenofibrate (FF). T1 also significantly decreased serum triglycerides (TG), total cholesterol (TC) and low density lipoprotein cholesterin (LDL) in methionine solution (Mets) induced hyperlipidemic mice. Moreover, hepatic transaminases (AST and ALT) were obviously ameliorated after treatment with T1 and the histological observation indicated that T1 ameliorated the injury in liver tissue and inhibited the hepatic lipid accumulation. In the livers of T1-administrated rat, the levels of PPARα related to lipids metabolism were up-regulated. Additional effects such as antioxidant, anti-inflammatory and H₂S releasing action confirmed and reinforced the activity of T1 as a potential multifunctional hypolipidemic and hepatoprotective agent.

Vibrational spectral analysis, XRD-structure, computation, exo⇔endo isomerization and non-linear optical crystal of 5-((5-chloro-1H-indol-2-yl)methylene)-1,3-diethyl-2-thioxodihy-dropyrimidine-4,6 (1H,5H)-dione

This work deals with the synthesis and characterization of the novel 5-((5-chloro-1H-indol-2-yl)methylene)-1,3-diethyl-2-thioxodihydro-pyrimidine-4,6(1H,5H)-dione π-bridge (D–A–D) donor–acceptor–donor compound. Its exo-isomer structure has been proven by XRD-single-crystal analysis for the first time. The IR, UV–Vis., MS, CHN-, ¹H and ¹³C NMR analysis were also carried out. The DFT-optimized structural-parameters were matched with the XRD-crystallographic data. The experimental-XRD-interactions in the lattice were compared to the computed Hirshfeld analysis (HSA), MEP map and Mulliken charge population. The DFT/6-311G(d) calculations like IR/B3LYP, TD-SCF, HOMO–LUMO, GRD and GIAO-NMR have been compared to their corresponding experimental parameters. Non-linear optical (NLO) crystal theoretical-analysis was carried out then compared to urea reference. The compound thermal activity was evaluated in an open-atmosphere by TG/DTG analysis.

Sustainable and scalable synthesis of polysubstituted bis-1,2,4-triazoles, bis-2-iminothiazolines and bis-thiobarbiturates using bis-N,N-disubstituted thioureas as versatile substrate

An expedient and tandem regioselective one-pot protocol for the sono-synthesis of bis-[1,2,4]-triazol-3-yl amines and bis-2-iminothiazolines from corresponding bis-1,3-disubstituted thioureas has been developed. The products' regioselectivity correlate well with the pK as of the parent amines, in which the amine possessing higher pK a goes to the ring nitrogen, whereas the other nitrogen remains flanked as an exocyclic nitrogen of the bis-triazole or bis-thiazole moieties. Further, the sonochemical preparation of both bis-5-(2-nitrobenzylidene) thiobarbiturates and bis-2-thioxoimidazolidine-4,5-diones from bis-1,3-disubstituted thioureas has also been achieved. The obtained bis-5-(2-nitrobenzylidene)thiobarbiturates easily underwent reductive cyclization to afford the corresponding bis-5-benzo[c]isoxazol-3-ylidenethiobarbiturates. The scope and limitations of these strategies have been studied. Moreover, the suggested methodologies have advantages such as broad functional group tolerance, mild conditions, operational simplicity and applicability on a gram scale. Furthermore, the protocols scored well in a number of green metrics, subsequently showing these approaches to be environmentally benign and sustainable processes.