Alkyl Derivatives Research Articles

X-ray diffraction and theoretical study of molecular and crystal structure of new crystalline aryl- and alkyl-substituted N-(adamantan-1-yl)amides: Similarities and differences

The molecular structure and crystal packing of new aryl and alkyl N-(adamantan-1-yl)amides derivatives А1–А7 were analyzed, and their intermolecular interaction parameters were found using X-ray diffraction, topological analysis within Bader's theory of “Atoms in molecules”, PIXEL method, and Hirshfeld surface analysis. N–H…O and С–Н…О hydrogen bonds and numerous Н…Н contacts are formed in the crystals of adamantylamides А1–А7. The adamantylamide molecules A1–A7 form a С(4) supramolecular chain synthon via N–H…O hydrogen bonds. An acetamide oxygen atom in the crystals of A1, A3–A5, and A7 is involved into unsymmetrical bifurcated bonds, in which one component is N–H…O and the other one is С–Н…О. The contribution of the O…Н contacts to the Hirshfeld surface is higher for alkyl adamantylamides than that for the aryl derivatives, whereas the packing index is lower for the alkyl derivatives than that for aryl one. The position of an acetamide group relative to adamantane framework in all structures is fixed by C–H…O intramolecular hydrogen bonds. The stabilization energy of the molecular pairs apparently depends on orientation of substituents and the mutual orientation of molecules in the pair that create favorable conditions for numerous intermolecular interactions.

Synthesis and inhibition profiles of N-benzyl- and N-allyl aniline derivatives against carbonic anhydrase and acetylcholinesterase – A molecular docking study

The alkyl and aryl derivatives of aniline are important starting materials in fine organic synthesis. Allyl bromide and benzyl chloride were taken as substrates for the alkylation reaction and as a halide ion scavenger. Triethylamine was utilized at reflux condition of N,N-dimethylacetamide (DMA). Novel synthesized N-benzyl and N-allyl aniline derivatives ( 1a-f ) were evaluated to be highly potent inhibitors for acetylcholinesterase (AChE) and carbonic anhydrases (hCAs). The half maximal inhibitory concentration (IC 50 ) of N-benzyl- and N-allyl aniline derivatives were calculated between 243.11 and 633.54 nM for hCA I, 296.32–518.37 nM for hCA II and 182.45–520.21 nM for AChE enzymes. On the other hand, K i values are in the range of 149.24 ± 15.59 to 519.59 ± 102.27 nM for AChE, 202.12 ± 16.21 to 635.31 ± 45.33 nM for hCA I and 298.57 ± 94.13 to 511.18 ± 115.98 nM for hCA II isoenzyme. Additionally, in silico molecular docking computations were performed with Autodock Vina program to support the experimental in vitro studies for both hCAs and AChE inhibitors. The in silico molecular docking results demonstrated that the scores are in good agreement with the experimental results.

Design, synthesis and glycosidase inhibition of C-4 branched LAB and DAB derivatives

Two series of C-4 alkylated and arylated LAB (1,4-dideoxy-1,4-imino-l-arabinitol) and DAB (1,4-dideoxy-1,4-imino-d-arabinitol) derivatives, synthesized in 6 steps from enantiomeric cyclic nitrones derived from l- and d-tartaric acid, were designed and assayed against various glycosidases. C-4 Branched LAB alkyl and phenyl derivatives 5La-d showed potent α-glucosidase inhibition, particularly against human lysosomal acid α-glucosidase; C-4 DAB derivatives 5Da-d, with small alkyl groups, showed enhanced inhibition of rat intestinal maltase and sucrase. Both enantiomeric C-4 arylated derivatives 5Lf-l and 5Df-l exhibited potent and selective α-glucosidase inhibition; and compound 5Li with a para-electron donating group (EDG) on its C-4 aryl group, showed the most potent rat intestinal sucrase inhibition. Docking studies showed similar hydrogen bonding modes for the iminosugar skeletons of DAB (1) and LAB (2) with ntMGAM,. While C-4 alkylated LAB derivatives showed high similarity in their binding modes with the active site of ntMGAM, binding modes of the DAB derivatives relied on the size of C-4 alkyl groups with methyl and butyl showed the optimum interactions. Furthermore, C-4 arylation improved the interactions of LAB derivatives with enzymes by T-shaped π-π stack with residue Trp-406; for C-4 arylated DAB derivatives, the π-π stack interactions were found with distinct planar distortions caused by EDGs or EWGs on the C-4 aryls. The results reported herein provided insights for the design and development of DAB and LAB related α-glucosidase inhibitors, and may also contribute to the future development of anti-viral, anti-diabetic and anti-Pompe disease drugs.

Porous Polymeric Membranes Doped with Halloysite Nanotubes and Oxygenic Polyoxometalates

AbstractEndowing anti‐fouling capabilities to water treatment membranes is a key feature for their long lifetime, but it continues to be a challenging task. Herein, a strategy for preparing composite membranes is reported comprising halloysite nanotubes (HNTs) as scaffolds to support a ruthenium substituted polyoxometalate (Ru4POM), with the goal of using evolved O2, resulting from the Ru4POM‐catalyzed H2O2 dismutation, as anti‐fouling agent. Two different amino alkyl derivatives, that is, a phosphonate and a silane, are grafted, respectively, in the lumen and on the surface of HNTs to support Ru4POM, and the resulting hybrid nanostructures are compared, in terms of catalytic efficiency and stability, to establish the most promising membrane additive. Porous polyether sulfone–based membranes are thus prepared to obtain a first proof of concept for this doping strategy. With respect to the former Ru4POM‐containing membranes, HNTs provide Earth‐abundant and low‐cost scaffolds for their efficient dispersion in the polymeric matrix. Preliminary tests on permeability and anti‐fouling behavior are finally discussed.

Evaluation Of Antioxidant Activity Of 1, 2, 4-Triazole Derivatives With Morpholine Moiety

The aim of the work was to study the antioxidant activity of 4-R-3- (morpholinomethyl)-4H-1,2,4-triazole-5-thioles and their alkyl derivatives in vitro using the method of non-enzymatic initiation of lipid peroxidation. Among the 45 compounds studied, 8 showed varying degrees of AOA. The most pronounced AOA has 4-amino-3-(morpholinomethyl)-4H-1,2,4-triazole-5-thiol. It was found that in most cases the introduction in alkyl-derivatives of 4-R-3-(morpholinomethyl)-4H-1,2,4-triazole-5-thioles free amino group or phenyl substituent to the N4 atom of the 1,2,4-triazole nucleus, accompanied with increasing of AOA for test substances. In almost all cases, the presence on the N4 atom of 1,2,4-triazole nucleus methyl or ethyl groups has the opposite effect, even in comparison with control groups.

RADIATION HARDNESS OF POLYSILOXANE-BASED SCINTILLATORS

Polysiloxane-based scintillators with different contant of aromatic chromophore groups have been obtained. 2,5-diphenyloxazole and its alkyl derivative were used as activators. The optical and scintillation properties of the obtained polysiloxane scintillators have been studied, and their radiation resistance has been determined. The prospect of using the material in fields with high dose loads is estimated.

Site-selective rhodium carbene transfer of 2 hydroxy-β-nitrostyrenes with diazo compounds En route to 2-alkylated benzofurans

The Rh(iii)-catalysed cascade vinylic C–H functionalization/carbene transfer/Michael addition sequence of 2-hydroxy-β-nitrostyrenes has been realized, delivering the 2-alkylated benzofuran derivatives as potential tyrosinase inhibitors.

Исследование примесного состава изотопно обогащенного германа 70GeH4 методом хромато-масс-спектрометрии

For the first time, the impurity composition of isotopically enriched germane 70GeH4 has been studied by gas chromatography-mass spectrometry. To separate impurities, we used a GS-GasPro capillary adsorption column 60 m × 0,32 mm with silica gel as a sorbent, GS-CarbonPLOT 25 m × 0,32 mm × 0,25 μm with a carbon sorbent and 25 m × 0,26 mm × 0,25 μm with sorbent polytrimethylsilylpropine. It has been shown that their use makes it possible to achieve a high resolution of the chromatographed substances. The identification of impurities was carried out by comparing their mass spectra with the data of the NIST library. Gases are found in germane, which are part of the atmosphere, C1 – C7 hydrocarbons, chlorine and oxygenated hydrocarbons, sulfur-containing substances, homologues and alkyl derivatives of germane. As a result of studying the composition of their mass spectra, the mass spectra of impurities 70GeC3H10 and 70GeC4H12, which are absent in the literature sources, were obtained and described for the first time. Concentrations of impurities in high-purity germane, as well as their distribution over fractions isolated during its rectification purification, have been determined. The detection limits of the identified substances were 2·10–7 – 1·10–4 mol. %.

RESEARCH INTO SORPTION PROCESS OF LEVOTHYROXINE WITH ALKYL-SUBSTITUTED CHITOSAN SCHIFF-BASED HYDROGEL

In order to reduce the side effects of thyroid hormone substitute levothyroxine sodium pentahydrate, its sorption with a quaternized salt of a new alkyl derivative of chitosan was studied. The drug amount in the salt (gel) is in micrograms, and the gel-levothyroxine is in the form of a complex that can show biological activity. With that end in view, a sorption process of levothyroxine sodium from an aqueous solution to the inside and surface of the hydrogel was carried out under static conditions. The capacity of the hydrogel depending upon the pH medium, the ionic strength, the hydrogel dose, the concentration of the drug and the temperature was studied. It was shown that the effective sorption of levothyroxine by chitosan-based hydrogel was optimal at pH of 6-8.5, at 50 mg/L concentration of levothyroxine in the presence of 10-50 mg of hydrogel dose but the sorption degree begins to decrease after T=40 °C. The isotherm results of sorption processes have been found to be subordinate mainly to Langmuir and to some extent Freundlich equations. It revealed that gel degradation in the oxidizing medium is about 70% within 2 weeks, and in the elastase and PBS medium is about 17-20%.

Practising organometallic chemistry in nineteenth century Australia: David Orme Masson and diethyl magnesium

By the late 1880s, the existence of alkyl derivatives of metals such as zinc and mercury was well established but diethyl magnesium had been poorly characterised and obtaining proof of its existence was a reasonable aim for chemists. Professor David Orme Masson and his student, Norman Wilsmore, at the university in the British colonial capital, Melbourne, accepted the challenge despite their distance from northern hemisphere centres of chemical research. The ‘tyranny of distance’ was tempered by their access to chemical journals and textbooks and by Masson’s connections at the ‘centre’, notably with William Ramsay. Wilsmore repeated the earlier experiments and also used methods that had been successful with other metals, but was unable to prepare diethyl magnesium. Masson rationalised this failure on the basis of the element’s position in the periodic classification of the elements that Mendeleev and Lothar Meyer had published, and on magnesium’s position on the atomic volume curve of Meyer, and concluded that diethyl magnesium could not exist. The weakness of these arguments was revealed when, near-coincidentally with Masson’s and Wilsmore’s publication of the results of their experiments, Philippe Löhr, working in Meyer’s laboratory, published successful syntheses of several alkyl magnesium derivatives by methods that had been unsuccessful in Wilsmore’s hands. Masson’s heuristic use of Meyer’s curve was unusual, and a notable feature of his approach to chemistry.

FENILPROPANOIDES COM AÇÃO ANTI-Trypanosoma cruzi ISOLADOS DE Baccharis ligustrina C. DC. (ASTERACEAE)

ANTI-Trypanosoma cruzi PHENYLPROPANOIDS ISOLATED FROM Baccharis ligustrina C. DC. (ASTERACEAE). In the present work, dried aerial parts of Baccharis ligustrina (Asteraceae) were subjected to microwave assisted extraction (MAE) using aqueous solution of 1-butyl-3-methylimidazolium bromide (BMImBr) and the obtained extract was successively partitioned using hexane and EtOAc. Using reduced amounts of extracts and efficient chromatographic steps, four acyl C6C3 derivatives (n-hexacosyl ferulate, n-hexacosyl, n-octacosyl, and n-triacontyl p-coumarates) were obtained from hexane phase whereas two C6C3 acids (ferulic and p-coumaric) were obtained from EtOAc phase. Isolated phenylpropanoids were evaluated against amastigote forms of parasite Trypanosoma cruzi. As result, it was observed that p-coumaric and ferulic acids were inactives whereas alkyl derivatives displayed EC50 values of 6.5 µmol L-1 (n-octacosyl p-coumarate), 9.3 µmol L-1 (n-triacontyl p-coumarate), 15.7 µmol L-1 (n-hexacosyl p-coumarate), and 32.2 µmol L-1 (n-hexacosyl ferulate). All tested compounds displayed reduced toxicity against NCTC cells (CC50 > 200 mmol L-1).

Antitrypanosomal activity of new semi-synthetic bergenin derivatives.

Bergenin and 11-O-(4'-O-methyl galloyl)-bergenin, previously isolated from Crassula capitella extract, were used as starting materials for the synthesis of eight derivatives; four derivatives 2a-2d were synthesized from bergenin through the formation of ester derivatives and four alkyl derivatives 4a-4d were synthesized from 11-O-(4'-O-methyl galloyl)-bergenin. The structures of the synthesized analogues were confirmed upon 1 H and 13 C NMR spectroscopic elucidation. Antileishmanial and antitrypanosomal activities of the synthesized derivatives were evaluated, compounds 11-O-(3',5' di-benzyl, 4'-O-methyl galloyl)-8,10-di-O-benzyl-bergenin (4c) and 11-O-(3',5'di-4-chlorobenzyl,4'-O-methyl galloyl)-8,10di-O-4-chlorobenzyl bergenin (4d) showed potent antitrypanosomal activity with IC50 values of 0.52 and 0.5μM, respectively and IC90 values of 0.66μM against T.brucei compared with IC50 and IC90 values of 21.7 and 50.3μM for the positive control difluoromethylornithine.

One-pot synthesis of novel substituted quinoxaline piperazine derivatives and their antimicrobial activities

The present investigation reports the preparation of 1-(4-(tolyl quinoxaline-2-yl) piperazine-1-yl) derivatives catalyzed via polymer supported reagents. We have developed novel quinoxaline piperazine derivatives from 2,3-dichloroquinoxaline, wherein one chloro group is substituted with an aryl group, and the other is substituted by alkyl and aryl piperazine derivatives, through aromatic nucleophilic substitution reaction, and Suzuki coupling reactions to substituted quinoxaline-piperazine derivatives (5a-5g) compounds. The synthesized compounds were identified using FTIR, 1H NMR, 13C NMR and LC-MS. The synthesized compounds were examined for their antimicrobial activity. The results indicated that 5d, 5f and 5 g compounds have exhibited well to moderate antibacterial activity with the zone of inhibition of 18, 22 and 21 mm for Escherichia coli (40 µg/mL), and 17, 19 and 17 mm for Staphylococcus aureus (40 µg/mL). Besides, 5f compound showed respectable results to moderate antifungal activity with the zone of inhibition of 21 mm for Aspergillus niger (40 µg/mL) and 19 mm for Candida albicans (40 µg/mL). The established synthetic route is beneficial to develop various key intermediates as well as active pharmaceutical ingredients for pharmaceutical applications.

Dehalogenation and Desulfonation from Aryl and Alkyl Compounds with a Cobalt Catalyst in the Presence of Alcohol

AbstractEasy dehalogenation of bromo‐, chloro‐aryl and alkyl derivatives is performed in the presence of a cobalt catalyst, manganese as reductant, and alcohol as hydrogen donor. This method tolerates a variety of functional groups with different electronic properties. Noteworthy examples of desulfonation are also reported.

Study of the Biological Activity of Alkyl Derivatives of Tetrahydroisoquinolines

A row of 1-alkyne (C6-C17) derivatives against tetrahydroisoquinoline have been synthesized. 1-alkyne (C6-C17) derivatives cytotoxicity against three lines of cancer cells and two lines of normal cells was studied. It was found that 1-tridecyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline exhibits a high cytotoxic effect with low toxicity to healthy cells. Antimicrobial activity of 1-alkyne (C6-C17) derivatives against 5 strains of bacteria and fungus was studied. It has been found that 1-nonyl-6,7-dimethoxy-1,3,4-tetrahydroisoquinoline exhibits strong antibacterial and antifungal effects.

Ester-Containing Imidazolium-Type Ionic Liquid Crystals Derived from Bio-based Fatty Alcohols

The need to take into account the life cycle of ionic liquids (ILs), from the sourcing of the raw materials involved in their synthesis to their disposal and degradation, has become paramount in the design of new IL-type molecular structures. In the case of 1-alkyl-3-methylimidazolium salts, one of the prominent IL families, there is an increasing demand for synthetic methods involving (i) substitution of the petro-based alkyl derivatives by readily available bio-sourced surrogates and (ii) functionalization of the alkyl tail with heterofunctional groups enabling the (bio)degradation of ILs after use. Herein, a straightforward and industrially viable synthesis of lipidic imidazolium salts is reported, starting from different bio-sourced fatty alcohols, including oleic, stearyl, and lauryl alcohols. This procedure is based on the acrylation of fatty alcohols, followed by the aza-Michael addition of the imidazole group onto the acrylate moiety. Subsequent quaternization, using either methyl iodide or methyl tosylate, provides a library of 1-alkylpropionate-3-methylimidazolium salts with various alkyl chain lengths (C18, C12, and C11) and incorporating different types of counteranions (iodide, tosylate, and tetrafluoroborate). These ester-containing analogues of classical 1-alkyl-3-methylimidazolium salts are all ILs, that is, with a melting point below 100 °C. In addition, most of them exhibit a liquid-crystal behavior and can be referred to as IL crystals (ILCs). The thermal stability, as well as the phase transitions of these ILs, has been investigated by thermogravimetric analysis, as well as differential scanning calorimetry, respectively, while the molecular structure into the crystalline phase and the mesophase is studied by X-ray scattering. Interestingly, ILCs featuring unsaturated alkyl tails exhibit a low melting point, close to room temperature, and the presence of the ester function is shown to provide an enhanced stabilization of the mesophase.

Rapid and Direct Photocatalytic C(sp3)−H Acylation and Arylation in Flow

AbstractHerein, we report a photocatalytic procedure that enables the acylation/arylation of unfunctionalized alkyl derivatives in flow. The method exploits the ability of the decatungstate anion to act as a hydrogen atom abstractor and produce nucleophilic carbon‐centered radicals that are intercepted by a nickel catalyst to ultimately forge C(sp3)−C(sp2) bonds. Owing to the intensified conditions in flow, the reaction time can be reduced from 12–48 hours to only 5–15 minutes. Finally, kinetic measurements highlight how the intensified conditions do not change the reaction mechanism but reliably speed up the overall process.

Rapid and Direct Photocatalytic C(sp3 )-H Acylation and Arylation in Flow.

Herein, we report a photocatalytic procedure that enables the acylation/arylation of unfunctionalized alkyl derivatives in flow. The method exploits the ability of the decatungstate anion to act as a hydrogen atom abstractor and produce nucleophilic carbon‐centered radicals that are intercepted by a nickel catalyst to ultimately forge C(sp3)−C(sp2) bonds. Owing to the intensified conditions in flow, the reaction time can be reduced from 12–48 hours to only 5–15 minutes. Finally, kinetic measurements highlight how the intensified conditions do not change the reaction mechanism but reliably speed up the overall process.

Mo-Catalyzed One-Pot Synthesis of N-Polyheterocycles from Nitroarenes and Glycols with Recycling of the Waste Reduction Byproduct. Substituent-Tuned Photophysical Properties.

A catalytic domino reduction–imine formation–intramolecular cyclization–oxidation for the general synthesis of a wide variety of biologically relevant N‐polyheterocycles, such as quinoxaline‐ and quinoline‐fused derivatives, and phenanthridines, is reported. A simple, easily available, and environmentally friendly dioxomolybdenum(VI) complex has proven to be a highly efficient and versatile catalyst for transforming a broad range of starting nitroarenes involving several redox processes. Not only is this a sustainable, step‐economical as well as air‐ and moisture‐tolerant method, but also it is worth highlighting that the waste byproduct generated in the first step of the sequence is recycled and incorporated in the final target molecule, improving the overall synthetic efficiency. Moreover, selected indoloquinoxalines have been photophysically characterized in cyclohexane and toluene with exceptional fluorescence quantum yields above 0.7 for the alkyl derivatives.

Functionally substituted arylhydrazones as building blocks in heterocyclic synthesis: Facile synthesis of pyrazoles, triazoles, triazines and quantum chemical studies

The arylhydrazones were treated with ethyl iodide, ethyl chloroacetate to afford the alkyl derivatives, which cyclized to the pyrazole derivatives, also, arylhydrazones were reacted with ethyl chloroformate to furnish the triazindione derivative. Reactions of arylhydrazones with hydroxylamine hydrochloride afforded the oxime derivative. Treatment of arylhydrazones with binucleophile reagents such as hydrazine hydrate and phenyl hydrazine gives the pyrazole derivatives. Treated of arylidine derivatives with malononitrile and hydrazine hydrate afforded the 4H-pyrane derivatives and pyrazole derivatives. The theoretical calculations optimization and frequency of synthesized compounds by Gaussian 09 with DFT by B3LYP method. The base set 6–31 G (d,p) to obtain descriptors explains the reactivity or stability of the synthesized compounds. It predicts the relation between theoretical descriptors computed which agree with experimental data.