42486-87-3Relevant academic research and scientific papers
Aromatic triazole foldamers induced by C-H...X (X = F, Cl) intramolecular hydrogen bonding
Shang, Jie,Gallagher, Nolan M.,Bie, Fusheng,Li, Qiaolian,Che, Yanke,Wang, Ying,Jiang, Hua
, p. 5134 - 5144 (2014)
Aryl-triazole oligomers based on isobutyl 4-fluorobenzoate and isobutyl 4-chlorobenzoate were designed and synthesized. Crystal structure and 1H-1H NOESY experiments demonstrate that the oligomers adopt stable helical conformation, which are induced by C5-H...X-C (X = F, Cl) intramolecular hydrogen bonding between triazole protons and halogen atoms. The stabilities of the folded conformations are confirmed by DFT calculations, which show that each C5-H...F-C planar interaction lowers the energy by ～3 kcal mol-1 on average, and by ～1 kcal mol-1 when C5-H...Cl-C bridges are formed. The hydrogen-bonding networks are disrupted in competitive hydrogen-bonding media such as DMSO, generating the unfolded oligomers.
New mono- and di-branched derivatives of Kryptofix K22 with N-4-methoxyamino-3,5-dinitrobenzoyl substituents. Synthesis and properties
Tudose, Madalina,Caproiu, Miron T.,Badea, Florin D.,Nedelcu, Georgian,Ionita, Petre,Constantinescu, Titus,Balaban, Alexandru T.
experimental part, p. 343 - 354 (2011/05/11)
Starting from the Kryptofix 22 azacrown compound, mono- and di-branched derivatives have been synthesized, by coupling with one or two 4-chloro-3,5-dinitrobenzoyl chloride units and then substituting the chlorine(s) on the aromatic ring(s) with methoxyami
Synthesis of Polyfunctionalized Biphenyls as Intermediates for a New Class of Liquid Crystals
Manka, Jason T.,Guo, Fengli,Huang, Jianping,Yin, Huiyong,Farrar, John M.,Sienkowska, Monika,Benin, Vladimir,Kaszynski, Piotr
, p. 9574 - 9588 (2007/10/03)
A series of hexa- and octasubstituted biphenyls containing halogen, amino, nitro, and propylthio substituents were prepared by metal-mediated convergent synthesis from halobenzene precursors. The Pd-assisted C-C coupling methods were ineffective in the fo
Enantioselective nucleophilic aromatic substitution with small-molecule chiral selectors
Snyder, Seth E.,Shvets, Alex B.,Pirkle, William H.
, p. 3605 - 3615 (2007/10/03)
Small-molecule rationally designed chiral selectors have been shown to influence the stereochemical outcome of a variety of organic transformations. For instance, in a recent report, we demonstrated that a chiral selector (in conjunction with an achiral phase-transfer catalyst) could selectively inhibit one enantiomer of electron-deficient aromatic amides from forming Meisenheimer adducts (Scheme 2). We now extend this methodology to performing enantioselective nucleophilic aromatic substitutions. Initial studies involved biphasic kinetic resolutions with a chiral selector in conjunction with an achiral phase-transfer catalyst (Scheme 3). The results are consistent with previous data taken for biphasic reactions (e.g., Scheme 1) where the chiral selector effectively shields the more highly complexed enantiomer from reaction. With neutral nucleophiles such as amines, the enantioselective nucleophilic aromatic substitutions can also be conducted in single-phase systems. Several examples are given.
Synthesis, selective aldose reductase inhibitory profile and antihyperglycaemic potential of certain parabanic acid derivatives
Nabil Aboul-Enein,El-Azzounya,Maklad,Attia,Wiese
, p. 329 - 350 (2007/10/03)
Synthesis and aldose reductase inhibitory profile of certain parabanic acid derivatives 1a-p is described. Also, the antihyperglycaemic potential of these compounds was studied. The most active inhibitors in this series were compounds 1 g, 1p, and 1o which showed inhibitory activity, 36.6, 90 and 91% respectively, at concentration 1 × 10-4. Their IC50 were 2 × 10-6, 7.5 × 10-8 and 5 × 10-8, respectively. Compound 1o exhibited pronounced antihyperglycaemic effect.
N-substituted 2-(2,6-dinitrophenylamino)propanamides: Novel prodrugs that release a primary amine via nitroreduction and intramolecular cyclization
Sykes, Bridget M.,Atwell, Graham J.,Hogg, Alison,Wilson, William R.,O'Connor, Charmian J.,Denny, William A.
, p. 346 - 355 (2007/10/03)
A series of N-dinitrophenylamino acid amides [(4-CONHZ-2,6- diNO'2Ph)N(R)C(X,Y)CONHPhOMe] were prepared as potential bioreductive prodrugs and reduced radiolytically to study their rates of subsequent intramolecular cyclization. Compounds bearing a free NH group (R = H) underwent rapid cyclization in neutral aqueous buffers (t(1/2) 1 min) following 4-electron reduction, with the generation of a N- hydroxydihydroquinoxalinone and concomitant release of 4-methoxyaniline. Amine release from analogous N-methyl analogues (R = Me) was relatively slow. These results are consistent with intramolecular cyclization of a monohydroxylamine intermediate. The high rates of cyclization/extrusion by these very electron-deficient hydroxylamines suggest that the process is greatly accelerated by the presence of an H-bonding 'conformational lock' between the anilino NH group and the adjacent o-nitro group (Kirk and Cohen, 1972). Changes in the phenylcarboxamide side chain or in C-methylation in the linking chain had little effect on the rate of cyclization. The model compounds had 1-electron reduction potentials in the range appropriate for cellular reduction (-373 mV for a measured example) and appeared suitable for development as prodrugs that release amine-based effectors following enzymic or radiolytic reduction. Prodrug examples containing 4-aminoaniline mustard and 5-amino-1-(chloromethyl)benz[e]indoline alkylating units were evaluated but were not activated efficiently by cellular nitroreductases. However, cell killing by the radiation-induced reduction of the latter prodrug was demonstrated.
Synthesis and evaluation of dinitroanilines for treatment of cryptosporidiosis
Benbow, John W.,Bernberg, Erin L.,Korda, Anna,Mead, Jan R.
, p. 339 - 343 (2007/10/03)
The efficacy of a series of dinitroaniline herbicide derivatives for the treatment of Cryptosporidium parvum infections has been studied. The lead compounds oryzalin (compound 1) and trifluralin (compound 2) have low water solubility (3 ppm) which was alleged to be a major contributor to their poor pharmacokinetic availability. Derivatives of compounds 1 and 2 were synthesized. In these derivatives the functionality at the C-1 amine position or the C-4 position was substituted with groups with various hydrophilicities to determine if a direct relation existed between water solubility and overall activity. The chlorinated precursors of these derivatives were also examined and were found to be less active in the C. parvum assays, a result in direct contrast to earlier work with Leishmania. Enhanced water solubility alone did not overcome the drug availability problem; however, several candidates with similar activities but with toxicities lower than those of the lead compounds were produced.
Receptor-based design of novel dihydrofolate reductase inhibitors: Benzimidazole and indole derivatives
Ohemeng,Roth
, p. 1383 - 1394 (2007/10/02)
Although many thousands of inhibitors of the enzyme dihydrofolate reductase (DHFR) have been synthesized, all of the very active compounds have been 2,4-diaminopyrimidines or very close analogues. This paper describes 2,4-diamino-6-benzylbenzimidazole (3b
Potential Antimitotic Agents. Synthesis of Some Ethyl Benzopyrazin-7-ylcarbamates, Ethyl Pyridopyrazin-7-ylcarbamates, and Ethyl Pyrido-as-triazin-7-ylcarbamates
Temple, Carroll,Rener, Gregory A.
, p. 3044 - 3050 (2007/10/02)
Ring analogues and derivatives of the 1,2-dihydropyridopyrazin-7-ylcarbamates (e.g., 29), antimitotic agents with antitumor activity, were prepared in the search for compounds with greater selectivity.Methods were developed for the conversion of su
