- Synthetic strategy and antiviral evaluation of diamide containing heterocycles targeting dengue and yellow fever virus
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High-Throughput screening of a subset of the CD3 chemical library (Centre for Drug Design and Discovery; KU Leuven) provided us with a lead compound 1, displaying low micromolar potency against dengue virus and yellow fever virus. Within a project aimed at discovering new inhibitors of flaviviruses, substitution of its central imidazole ring led to synthesis of variably substituted pyrazine dicarboxylamides and phthalic diamides, which were evaluated in cell-based assays for cytotoxicity and antiviral activity against the dengue virus (DENV) and yellow fever virus (YFV). Fourteen compounds inhibited DENV replication (EC50 ranging between 0.5 and 3.4 1/4M), with compounds 6b and 6d being the most potent inhibitors (EC50 0.5 1/4M) with selectivity indices (SI) > 235. Compound 7a likewise exhibited anti-DENV activity with an EC50 of 0.5 1/4M and an SI of >235. In addition, good antiviral activity of seven compounds in the series was also noted against the YFV with EC50 values ranging between 0.4 and 3.3 1/4M, with compound 6n being the most potent for this series with an EC50 0.4 1/4M and a selectivity index of >34. Finally, reversal of one of the central amide bonds as in series 13 proved deleterious to the inhibitory activity.
- Saudi, Milind,Zmurko, Joanna,Kaptein, Suzanne,Rozenski, Jef,Gadakh, Bharat,Chaltin, Patrick,Marchand, Arnaud,Neyts, Johan,Van Aerschot, Arthur
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p. 158 - 168
(2016/06/09)
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- Radical-mediated dehydrative preparation of cyclic imides using (NH4)2S2O8-DMSO: Application to the synthesis of vernakalant
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Ammonium persulfate-dimethyl sulfoxide (APS-DMSO) has been developed as an efficient and new dehydrating reagent for a convenient one-pot process for the synthesis of miscellaneous cyclic imides in high yields starting from readily available primary amines and cyclic anhydrides. A plausible radical mechanism involving DMSO has been proposed. The application of this facile one-pot imide forming process has been demonstrated for a practical synthesis of vernakalant.
- Garad, Dnyaneshwar N.,Tanpure, Subhash D.,Mhaske, Santosh B.
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supporting information
p. 1008 - 1016
(2015/08/18)
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- Water mediated, environmentally friendly, step-wise, tandem & one-pot syntheses of 2-(1H-benzo[d]imidazole-2-yl)-N-arylbenzamides
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Water mediated and environmentally friendly, step-wise, tandem & one-pot syntheses of 2-(1H-benzo[d]imidazole-2-yl)-N-arylbenzamide derivatives have been developed by simply combining phthalic anhydride, anilines and phenylenediammonium dihydrogenphosphate. This reaction has an easy workup, provides excellent yields, and uses water as the solvent which is considered to be relatively environmentally benign.
- Reddy, Yervala Dathu,Ramana Reddy, Chittireddy Venkata,Dubey, Pramod Kumar
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p. 2974 - 2979
(2014/01/06)
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- An expeditious synthesis of imides from phthalic, maleic and succinic anhydrides and chemoselective C=C reduction of maleic amide esters
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Phthalic, maleic and succinic anhydrides have been reacted with aromatic amines to obtain the corresponding monoacid monoamides. The latter have been each transformed into the corresponding cyclic imide derivatives by treating with SOCl2. Alternatively, anhydrides have been reacted with methanolic KOH to obtain monomethyl ester derivatives which on reaction with aromatic amines in the presence of EDC. HCl and HOBt give cyclic imide derivatives. Reaction of monoacid monoamides independently, with SOCl 2 at 0-5°C give the monoamide monoester derivatives. Treatment of monoamide monoester of malic anhydride with NaBH4 leads to the unusual reduction of C=C grouping as well as the carbonyl group of the ester group to from monoamide monoalcohol of succinic anhydride. Preparation of monoamide monoalcohol of succinic anhydride can also be achieved by chemoselective reduction of monoamide monoester of malic anhydride with Mg turnings yielding monoamide monoester of succinic anhydride followed by reduction of the latter with NaBH4.
- Kumar, Padam Praveen,Reddy, Y. Dathu,Kumari, Y. Bharathi,Devi, B. Rama,Dubey
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p. 392 - 398
(2014/05/06)
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- Aza-DielsAlder reaction between N-aryl-1-oxo-1H-isoindolium ions and tert-enamides: Steric effects on reaction outcome
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The synthesis of 5-substituted 6,6a-dihydroisoindolo[2,1-a]quinolin-11(5H)- ones via [4 + 2] imino-DielsAlder cyclization from N-aryl-3- hydroxyisoindolinones and N-vinyl lactams under Lewis acid-catalysed anhydrous conditions is reported. Reactions of N-(2-substituted-aryl)-3- hydroxyisoindolinones with N-vinylpyrrolidone under identical conditions resulted in the formation of 2-(2-substitued-aryl)-3-(2-(2-oxopyrrolidin-1-yl) vinyl)isoindolin-1-one analogues indicating steric hinderance as the cause of deviation. The probable mechanism of the reaction based on the results from X-ray crystallography and molecular modelling is discussed.
- Jha, Amitabh,Chou, Ting-Yi,ALJaroudi, Zainab,Ellis, Bobby D.,Cameron, T. Stanley
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supporting information
p. 848 - 857
(2014/05/06)
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- A facile and green synthesis of N-substituted imides
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Anhydrides 1, 6 and 10 have been reacted, independently, with aromatic primary amines 2 in solid phase by simple physical grinding of reactants with p-toluenesulphonicacid as a catalyst to yield corresponding open chain derivatives, monoacid monoamides3,7 and 11 respectively. The latter have each been transformed into the corresponding cyclic derivatives, i.e. imides 5, 9 and 13 respectively in solid phase by simple physical grinding of each with K 2CO3, alkylating agent and tetrabutylammoniumbromide as a catalyst with short reaction times. These cyclic imides can also be obtained by physical grinding of each of 3, 7 and 11 with dicyclohexylcarbodimide as a dehydrating agent in solid phase.
- Kumar, Padam Praveen,Rama Devi,Dubey
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p. 1166 - 1171
(2013/09/24)
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- Chemoselective acylation of amines in aqueous media
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Amines are efficiently acylated by both cyclic and acyclic anhydrides by dissolving them in an aqueous medium with the help of a surfactant, sodium dodecyl sulfate (SDS). Cyclic and acyclic anhydrides react with equal ease with an amine, and amines with various stereo-electronic factors react at the same rates with an anhydride. Chemoselective acylation of amines in the presence of phenols and thiols and of thiols in the presence of phenols has been achieved. No acidic or basic reagents are used during the reaction. No Chromatographic separation is required for isolation of the acylated products. Reactions in a neutral aqueous medium, easy isolation of products, and innocuous by-products make the present method a green chemical process. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Naik, Sarala,Bhattacharjya, Gitalee,Talukdar, Bandana,Patel, Bhisma K.
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p. 1254 - 1260
(2007/10/03)
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- The cyclisation of substituted phthalanilic acids in acetic acid solution. A kinetic study of substituted N-phenylphthalimide formation
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One novel and ten known substituted 3′- and 4′-phthalanilic acids have been prepared. These have been cyclised to two novel and nine known substituted N-phenylphthalimides by heating with glacial acetic acid. Both phthalanilic acids and imides have been characterised in detail and spectroscopic data are given. The kinetics of cyclisation for phthalanilic acids has been examined in detail, and it has emerged that a complex mechanism is operating. This initially involves a reversible, solvent assisted intramolecular nucleophilic attack by amide nitrogen on the carboxylic acid carbonyl. Clear evidence is seen for a long-lived intermediate as a precursor to imide formation. The observed kinetics are rationalised using a model of rapid pre-equilibration, followed by the slow breakdown of the intermediate to imide. Observed rate constants for pre-equilibration show a well behaved, linear Hammett plot (ρ = -1.1), whereas those for formation of imide do not.
- Perry, Christopher J.,Parveen, Zahida
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p. 512 - 521
(2007/10/03)
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- Reaction of cyclic anhydrides with aromatic amines: Part I - Synthesis of anilinic acids from phthalic anhydride
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Some unreported anilinic acids 5a-j and 7 have been synthesised and their spectral data reported. Their in vitro insecticidal screening as protectants of maize (Zea mays) against Sitophilus zeamais shows 2-(N-naphthylcarbamoyl)benzoic acid 7 to be the most active member of the series.
- Omuaru, Victor O. T.,Boisa, N.,Obuzor, G. U.
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p. 704 - 706
(2007/10/03)
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- PROTONATION OF REAGENTS AND ACID-BASE CATALYSIS IN ACYLATION
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The kinetic characteristics of the model reaction of electron transfer and the reaction of acylation of aromatic amines by aromatic acid anhydrides were investigated as a function of the concentration of acid catalyst and a correlation was established between the type of this function and the characteristics of protonation of the amines.The rate constants of the catalytic and noncatalytic flows of the forward and reverse reactions in the phthalic anhydride-p-toluidine system were determined as a function of the molarity and proton-acceptor properties of the solvent.The mechanism of acid-base catalysis was examined as a sequence of proton and electron transfer processes. Keywords: catalysis, kinetics, protonation.
- Kalnin'sh, K. K.
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p. 822 - 828
(2007/10/02)
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- ACID CATALYSIS IN THE AMINOLYSIS OF MONOPHENYL PHTHALATE IN APROTIC SOLVENTS. PART III. THE EFFECTIVENESS OF INTRAMOLECULAR ACID CATALYSIS IN THE AMINOLYSIS OF MONOPHENYL PHTHALATE IN DIOXANE
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On the basis of preliminary kinetic investigations, it was assumed that the aminolysis of monophenyl phthalate proceeds according to two parallel pathways (I and II).This reaction has been found to proceed by one of the mentioned pathways or both of them in parallel, depending on the substrate concentration, reactivity of the nucleophilic agent, or solvent properties.Such a complex mechanism of the studied reaction is due to the fact that the carboxylic group is adjacent to the reaction center.Intramolecular acid catalysis has ben found to by highly effective in the monoester aminolysis.The aminolysis of phenyl benzoate, in the presence of acetic acid and 2,4-dinitrophenol as catalysts (intermolecular acid catalysis), has been studied for comparative purposes.
- Bojanowska, Irena,Jasinski, Tadeusz
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p. 101 - 111
(2007/10/02)
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- ACID CATALYSIS IN THE AMINOLYSIS OF MONOPHENYL PHTHALATE IN APROTIC SOLVENTS. PART II. AMINOLYSIS OF PHTHALIC ANHYDRIDE WITH ANILINE AND ITS DERIVATIVES IN DIOXANE
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Kinetic investigations of the aminolysis of phthalic anhydride with aniline and its derivatives have confirmed the autocatalytic character of this reaction.Rate constants of this process have been compared with the respective constants of the cyclization of monophenyl phthalate.It follows from this comparison that aminolysis of monophenyl phthalate proceeding according to pathway I is a consecutive reaction with the formation of an unstable, intermediate product.The kinetics of this reaction is determined by the cyclization process.
- Bojanowska, Irena,Jasinski, Tadeusz
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p. 465 - 470
(2007/10/02)
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- Preparation and Characterisation of Chromium(III) Complexes of Maleanilic and Phthalanilic Acids
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The complexes of the type , where A-A - maleanilic and phthalanilic acids, and their 4-methyl, 4-chloro, 4-nitro and 1-naphthyl derivatives have been prepared.The magnetic, conductance, ir and electronic spectral studies indicate their octahedral structure.
- Sharma, C. L.,Arya, R. S.,Narvi, S. S.
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p. 267 - 269
(2007/10/02)
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