New 2-pyrone-based hydrazones: Synthesis,spectral characterisation,UV–visible study and evaluation of the antiradicalar activity

The synthesis of new 2-pyrone-based hydrazones has been prepared by the coupling of 6-methyl-2H-furo[3,2-c]pyran-3,4-dione with diazonium salts, obtained by diazotization of aniline derivatives. The structure of all compounds was established by spectroscopic methods, and the structure of the more stable conformer was theoretically confirmed by the potential energy profile analysis. The prepared 2-pyrone-based hydrazone dyes were acetylated and both groups of compounds showed moderate to good radical scavenging activity.     

Clifford Wavelet Entropy for Fetal ECG Extraction

Analysis of the fetal heart rate during pregnancy is essential for monitoring the proper development of the fetus. Current fetal heart monitoring techniques lack the accuracy in fetal heart rate monitoring and features acquisition, resulting in diagnostic medical issues. The challenge lies in the extraction of the fetal ECG from the mother ECG during pregnancy. This approach has the advantage of being a reliable and non-invasive technique. In the present paper, a wavelet/multiwavelet method is proposed to perfectly extract the fetal ECG parameters from the abdominal mother ECG. In a first step, due to the wavelet/mutiwavelet processing, a denoising procedure is applied to separate the noised parts from the denoised ones. The denoised signal is assumed to be a mixture of both the MECG and the FECG. One of the well-known measures of accuracy in information processing is the concept of entropy. In the present work, a wavelet/multiwavelet Shannon-type entropy is constructed and applied to evaluate the order/disorder of the extracted FECG signal. The experimental results apply to a recent class of Clifford wavelets constructed in Arfaoui, et al. J. Math. Imaging Vis. 2020, 62, 73–97, and Arfaoui, et al. Acta Appl. Math. 2020, 170, 1–35. Additionally, classical Haar–Faber–Schauder wavelets are applied for the purpose of comparison. Two main well-known databases have been applied, the DAISY database and the CinC Challenge 2013 database. The achieved accuracy over the test databases resulted in Se = 100%, PPV = 100% for FECG extraction and peak detection.     

Temperature Effect on Liquid-Liquid Phase Equilibria of Aqueous Solutions of Fluorobenzene in Ethanol at the Pressure 101.2 kPa

Solubilities and liquid-liquid equilibrium (LLE) data for (water + ethanol + fluorobenzene) solutions are determined at T = (288.15, 298.15, 308.15) K and atmospheric pressure. The titration method is used to construct the binodal curves. All measured solubilities and liquid-liquid equilibrium data are reproduced quantitatively by empirical equations and the NRTL activity coefficient model. The correlated data are consistent to better than 0.3% in phase composition. The studied temperatures have a small effect on the phase equilibrium properties of the investigated systems. The influence of water concentration on the distribution coefficient of ethanol in the coexistent liquid phases and on the fluorobenzene selectivity is important. Practically, fluorobenzene may well be used to produce absolute alcohol.     

New synthesis of two tridentate bipyrazolic compounds and their cytotoxic activity tumor cell lines

Two new tripodal compounds - 4-{bis[(3,5-dimethyl-1H-pyrazole-1-yl)methyl]amino}butane-1-ol (1); ethyl 1-[((2-hydroxyethyl){[3-(ethoxycarbonyl)-5-methyl-1H-pyrazole-1-yl]methyl} amino)methyl]-5-methyl-1H-pyrazole-3-carboxylate (2) were reported. The evaluation of the cytotoxic properties in vitro of these ligands, was examined on two tumor cell lines - P815 (mastocytome murine) and Hep (carcinoma of human larynx). The concentration required to induce 50% of lysis (IC(50)) was more pronounced against P815 cell line (IC(50): 39.42 microg mL(-1) for the compound 1 and 97.74 microg mL(-1) for the compound 2) than the Hep cell line (IC(50): 83.49 microg mL(-1) for compound 1 and 185.30 microg mL(-1) for compound 2). Statistical analysis shows that the compound 1 is two to three folds more cytotoxic than the compound 2 (p < 0.05). Interestingly, the cytotoxic activity depends strongly on both the substituents linked to the aminic nitrogen and pyrazolic rings.     

An efficient synthesis of 2,6-disubstituted benzobisoxazoles: new building blocks for organic semiconductors

2,6-Disubstituted benzobisoxazoles have been synthesized by a highly efficient reaction of diaminobenzene diols with various orthoesters. The scope of this new reaction for the synthesis of substituted benzobisoxazoles has been investigated using four different orthoesters. The utility of these compounds as building blocks for the synthesis of conjugated polymers is demonstrated.     

Ring-closing metathesis towards functionalised pentacyclic steroids

A new synthetic pathway towards pentacyclic steroids was described via a ring-closing metathesis reaction as the key step.     

Efficient Synthesis of Chiral 1,1′‐Sulfonyl Bisaziridines

An efficient three‐step synthesis of chiral 1,1′‐(sulfonyl)bisaziridines is described. Preparation of these compounds was carried out easily starting from N,N′‐sulfonyl bis‐(α‐L‐aminoester) to afford the title compounds in very good yields. These 1,1′‐(sulfonyl)bisaziridines can constitute interesting synthetic building blocks.     

Synthesis and structural study of new substituted chiral sulfamoyl oxazolidin-2-ones

The synthesis of new series of oxazolidinones having sulfonamide moieties is described. These compounds are synthesized in good yield starting prochiral 1,3-dichloro-2-propanol and chlorosulfonyl isocyanate. This strategy involves the formation of carboxylsulfamide by carbamoylation–sulfamoylation reaction followed by intermolecular cyclization. In order to determine the enantioselectivity during the cyclization step, X-ray studies of products are performed.