“…It was found that the reaction under basic catalysis conditions also proceeds with the formation of two derivatives 60a and 61a (Scheme 18 ). 61 Scheme 18 …”
Section: The Reaction Of Aminobenzimidazoles With Bifunctional Synthetic Equivalentsmentioning
Nitrogen-containing heterocyclic compounds are the basis of many natural and synthetic biologically active substances. 1 More than two-thirds of the known drugs used in clinical practice contain heterocyclic and, above all, nitrogen-containing fragments within their structure. Over the past decades, the chemistry of aza-heterocycles has received considerable attention due to the wide spectrum of their biological activity and numerous therapeutic applications in medicine.Of nitrogenous heterocycles, azoloazines containing fragments similar to the natural heterocycles purines and pyrimidines are currently of great practical importance. Thus, non-natural nucleosides abacavir, famciclovir, remdesivir are known, which are the products of structural modifications of all the components of the nucleotide exhibiting excellent indicators of antiviral action (Fig. 1). [2][3][4] In addition to the generally accepted nucleoside forms, the azoloazines themselves are relevant in the search for means of combating diseases on a global scale. Nitroazolo- [5,1-c][1,2,4]triazines and nitroazolo [1,5-a]pyrimidines, a new family of antiviral compounds has been found. 5 The
“…It was found that the reaction under basic catalysis conditions also proceeds with the formation of two derivatives 60a and 61a (Scheme 18 ). 61 Scheme 18 …”
Section: The Reaction Of Aminobenzimidazoles With Bifunctional Synthetic Equivalentsmentioning
Nitrogen-containing heterocyclic compounds are the basis of many natural and synthetic biologically active substances. 1 More than two-thirds of the known drugs used in clinical practice contain heterocyclic and, above all, nitrogen-containing fragments within their structure. Over the past decades, the chemistry of aza-heterocycles has received considerable attention due to the wide spectrum of their biological activity and numerous therapeutic applications in medicine.Of nitrogenous heterocycles, azoloazines containing fragments similar to the natural heterocycles purines and pyrimidines are currently of great practical importance. Thus, non-natural nucleosides abacavir, famciclovir, remdesivir are known, which are the products of structural modifications of all the components of the nucleotide exhibiting excellent indicators of antiviral action (Fig. 1). [2][3][4] In addition to the generally accepted nucleoside forms, the azoloazines themselves are relevant in the search for means of combating diseases on a global scale. Nitroazolo- [5,1-c][1,2,4]triazines and nitroazolo [1,5-a]pyrimidines, a new family of antiviral compounds has been found. 5 The
“…The 1 H NMR spectrum from 6 showed several signals at 0.94 ppm for methyl group; at 1.12 to 2.40 and 2.58 to 8.08 ppm for steroid moiety; at 2.54 ppm for methyl groups bound to sulfur atoms ( Figure 6). 13 C NMR spectra showed chemical shifts at 15.44 ppm for methyl group F I G U R E 2 Synthesis of a carbonitrile-steroid derivative (5). Conditions and reagents: method A; dimethyl sulfoxide/reflux.…”
Section: Synthesis Of a Nitro-steroiddicarbonimidoyl Dichloride Dermentioning
confidence: 99%
“…[4] Other data showed the synthesis of some polycyclic imidazolidinones via reaction of α-ketoamides cyclic with secondary amines, using benzoic acid as catalyst. [5] In addition, a report has shown the preparation of some polycyclic aromatic iodides from 2-(arylethynyl)biphenyls and iodine monochloride. [6] On the other hand, there are some studies that show the preparation of several polycyclic bound to steroid nucleus; for example, the synthesis of compound 20S,20R-12,23-cyclo-22,26-epoxycholesta-5,11,22-triene-3β-16β-diyl diacetate from 12-oxosapogenin acetate, and boron trifluoride diethyl etherate.…”
Section: Introductionmentioning
confidence: 99%
“…[7] Additionally, a report showed the condensation of 16-dehydropregnenolone acetate with 2-aminobenzimidazole to form a pyrimidobenzimidazol-steroid derivative. [5] Furthermore, a hexacyclic-steroid derivative was prepared from 6-methyleneandrost-4-ene-3,17-dione and a quinone analog. [6] Also a study showed the synthesis of compound 17-amino-6,15-dihydro-7H-11-oxa-15,16-diazacyclopenta[a]phenanthren-12-one via the reaction of 2-oxo-4-sec-amino-methylsulfanyl-5,6-dihydro-2H-benzo [h]chromone and hydrazine.…”
Several studies for the synthesis of polycyclic derivatives have been reported; however, there is little information on the preparation of steroid‐polycyclic derivatives. In this way, the aim of this study was to synthesize a bismethylsulfanyl‐steroid‐azetyl butanol derivative (compound 10) from 2‐nitroestrone. The chemical structure was evaluated through both 1H NMR and 13C NMR or spectroscopic analysis. The results showed a good yielding from 10. It is noteworthy that the reagents used in this investigation are not expensive and do not require special conditions for handling.
“…To mimic the solvent environment effect, the polarizable conductor calculation model (CPCM [30]) was used. This theory level, not being computationally demanding, was extensively validated in the past on a number of different problems, like studies on reaction mechanisms [31], equilibrium states [32], and structural analysis of tocopherol-related antioxidants [29]. To account for orbital relaxation upon immersion in solvent, the geometry optimizations were carried out in solutions.…”
Vitamin E is the most active natural lipophilic antioxidant with a broad spectrum of biological activity. α-Tocopherol (α-T), the main representative of the vitamin E family, is a strong inhibitor of lipid peroxidation as a chain-breaking antioxidant. Antioxidant and antiradical properties of vitamin E result from the presence of a phenolic hydroxyl group at the C-6 position. Due to stereoelectronic effects in the dihydropyranyl ring, the dissociation enthalpy for phenolic O–H bond (BDEOH) is reduced. The high chain-breaking reactivity of α-T is mainly attributed to orbital overlapping of the 2p-type lone pair on the oxygen atom (O1) in para position to the phenolic group, and the aromatic π-electron system. The influence of the O1 atom on the antioxidant activity of vitamin E was estimated quantitatively. The all-rac-1-carba-α-tocopherol was synthesized for the first time. Along with model compounds, 1-carba-analog of Trolox and its methyl ester were screened for their in vitro antioxidant activity by inhibition of styrene oxidation, and for the radical-reducing properties by means of 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH) scavenging assay. To study the antioxidant activity, density functional theory (DFT) was also applied. Reaction enthalpies related to HAT (hydrogen atom transfer), SET–PT (sequential electron transfer—proton transfer), and SPLET (sequential proton loss—electron transfer) mechanisms were calculated.
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