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Benzamide
Selected AbstractsN-(Nitrophenyl) Benzamide and Benzenesulfonamide Derivatives by Nucleophilic Aromatic Substitution.CHEMINFORM, Issue 10 2005Richard A. Bunce Abstract For Abstract see ChemInform Abstract in Full Text. [source] Tagging (Arene)ruthenium(II) Anticancer Complexes with Fluorescent LabelsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 18 2007Fabio Zobi Abstract Fluorescent (arene)ruthenium(II) complexes have been prepared by tagging a small fluorogenic reporter onto the chelating ligand of complexes of the type [(,6 -arene)RuCl(Z)]+ (Z = chelating ligand). Complexes [(,6 - p -cym)RuCl(NNO)](Cl) (2), [(,6 - p -cym)RuCl(L3)](Cl) (3) and [(,6 - p -cym)RuCl(L4)](Cl) (4) {p -cym = p- cymene, NNO = 2-[(2-aminoethyl)amino]ethanol, L3 = 2-[(2-aminoethyl)amino]ethyl-2-(methylamino)benzoate and L4 = N -{2-[(2-aminoethyl)amino]ethyl}-2-(methylamino)benzamide} were obtained in good yield from the reaction of the Ru dimer [(,6 - p -cym)RuCl2]2 (1) and the corresponding ligand. The compounds have been fully characterized and their X-ray crystal structures are reported. Compounds 3 and 4 show a photoluminescence response centered at 435 nm with partial fluorescence quenching of the fluorogenic reporters L3 and L4 upon coordination to the metal center. Species 2,4 show good solubility both in water and organic solvents. In water, 2,4 readily hydrolyze to form the aqua complexes. These are stable at acidic pH forming 10,15,% of the corresponding hydroxido complexes in buffered solution (25 mM HEPES) as the pH is raised to a physiological value (pH = 7.44). Under these conditions, 4 (but not 2 or 3) undergoes a fast pH-dependent reversible intramolecular rearrangement. Experimental data and semiempirical calculations indicate that the major species arising from this transformation is a complex with a tridentate chelating ligand following deprotonation at the nitrogen atom of the amide group. Esterase-catalyzed hydrolysis of 3 liberates isatoic acid (MIAH) and generates 2 indicating that the complex is a substrate for the enzyme. Complexes similar to 3 may have potential for esterase-activated Ru-based prodrug delivery systems.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Aromatic and Benzylic C,H Bond Functionalization Upon Reaction between Nitriles and Perfluoroalkyl SulfoxidesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 31 2009Yohan Macé Abstract We studied the thermal behavior of some intermediates formed by reaction of nitriles with perfluoroalkyl sulfoxides upon trifluoromethanesulfonic anhydride activation. Bistriflate ketal 3, precursor of sulfilimine 1, may undergo a rearrangement to sulfanyl nitrile 5 after triflic acid elimination under thermal conditions. With p -tolyl trifluoromethyl sulfoxide, remote triflic acid elimination from intermediate 4 leads to benzamide 8 formation. These reactions involve, respectively, selective functionalization of the aromatic ortho C,H bond or the benzylic C,H bond para to the sulfoxide group. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Efficient Cross-Coupling Reactions of Nitrogen Nucleophiles with Aryl Halides in WaterADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2009Yong-Chua TeoArticle first published online: 17 MAR 200 Abstract A facile and practical strategy has been developed for the N -arylation of nitrogen nucleophiles with aryl halides catalyzed by a combination of iron(III) chloride [FeCl3] and dimethylethylenediamine (dmeda) in water. A variety of nitrogen nucleophiles including pyrazole, indole, 7-azaindole and benzamide afforded the N -arylated products in the presence of the catalytic system (in up to 88% yield). [source] Weak inhibitors protect cholinesterases from strong inhibitors (paraoxon): in vitro effect of tiaprideJOURNAL OF APPLIED TOXICOLOGY, Issue 6 2005G. A. Petroianu Abstract Weak and reversible inhibitors of cholinesterases, when administered before potent organophosphorus inhibitors (pretreatment), have the ability, to a certain extent, to protect enzymes from inhibition. Such a protective effect was demonstrated in vitro for metoclopramide and ranitidine. The putative mode of protective action of these substances is, when administered in excess, competition for the active site of the enzyme with the more potent organophosphate. The present paper presents results using another benzamide with weak cholinesterase inhibitory properties: tiapride (TIA). The purpose of the study was to quantify in vitro the extent that TIA conferred protection, using paraoxon (POX) as an inhibitor, and to compare the results with existing data obtained using TIA as a protective agent against dichlorvos (DDVP). POX is a highly toxic non-neuropathic organophosphate. While the use of parathion (the inactive prodrug which is metabolically converted to POX) has been restricted in most countries, the organophosphate is still responsible for a large number of accidental or suicidal exposures. DDVP is a moderately toxic, non-neuropathic organophosphate. Red blood cell (RBC) acetylcholinesterase (AChE) activities in whole blood and butyrylcholinesterase (BChE) activities in human plasma were measured photometrically in the presence of different POX and TIA concentrations and the IC50 was calculated. Determinations were repeated in the presence of increasing TIA concentrations. The IC50 of POX increases with the TIA concentration in a linear manner. The protective effect of tiapride on cholinesterase could be of practical relevance in the pretreatment of organophosphate poisoning. It is concluded that in vivo testing of TIA as an organophosphate protective agent is warranted. Copyright © 2005 John Wiley & Sons, Ltd. [source] Synthesis and activity of four (N,N -dimethylamino)benzamide nonsteroidal anti-inflammatory drugs based on thiazole and thiazolineJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 1 2006Daniel E. Lynch Four compounds derived from 2-aminothiazole and 2-amino-2-thiazoline were prepared by coupling the respective bases with the acid chlorides of either 3- or 4-(N,N -dimethylamino)benzoic acid. Products were identified using infrared spectroscopy, 1H NMR spectroscopy and electrospray mass spectroscopy and in two cases by single-crystal X-ray diffraction. Of the four, N -(thiazol-2-yl)-3-(N,N -dimethylamino)-benzamide (1), N -(thiazolin-2-yl)-4-(N,N -dimethylamino)benzamide (2), N -(thiazolin-2-yl)-3-(N,N -dimethylamino) benzamide (3) and N -(thiazolin-2-yl)-4-(N,N -dimethylamino)benzamide (4), the hydrochloride salts of compounds 3 and 4 showed anti-inflammatory activity across a concentration range of 10,2,5 × 10,4M while 3 (at a concentration of 10,5M) was found to have no adverse effect on myocardial function. The X-ray crystal structure of 2 and the 1:1 adduct structure of 3 with 3-(N,N -dimethylamino)benzoic acid are reported. [source] One-pot synthesis of the indole derivative 4-chloro-3-sulphamoyl- N -(2,3-dihydro-2-methyl-1H -indol-1-yl)benzamide (indapamide)JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 1 2004Barbara Ziobro New methods for the synthesis the indole derivative, Indapamide (1), using mixed anhydrides of the general formula R1COOCOOR2 (2) or DCC (N,N'-dicyclohexylcarbodiimide) (3), are described. [source] Synthesis of a series of carbon-14 labelled 4-aminoquinazolines and quinazolin-4 (3H)-onesJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 11 2009Nader Saemian Abstract 4-Aminoquinazolines and quinazolin-4 (3H)-ones, both labelled with carbon-14 in the 4-position, were prepared from 2-aminobenzonitrile-[cyano- 14C] and 2-aminobenzoic acid-[carboxy - 14C] or 2-amino- benzamide-[carboxy - 14C], respectively, using rapid, one-pot procedures under microwave enhanced conditions. Copyright © 2009 John Wiley & Sons, Ltd. [source] Synthesis and preliminary in vivo evaluation of 4-[18F]fluoro- N -{2-[4-(6-trifluoromethylpyridin-2-yl)piperazin-1-yl]ethyl}benzamide, a potential PET radioligand for the 5-HT1A receptorJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 9 2004M. Vandecapelle Abstract 4-Fluoro- N -{2-[4-(6-trifluoromethylpyridin-2-yl)piperazin-1-yl]ethyl}benzamide is a full 5-HT1A agonist with high affinity (pKi=9.3), selectivity and a c log P of 3.045. The corresponding PET radioligand 4-[18F]fluoro- N -{2-[4-(6-trifluoromethylpyridin-2-yl)piperazin-1-yl]ethyl}benzamide was synthesized by nucleophilic aromatic substitution on the nitro precursor. The fluorinating agent K[18F]F/Kryptofix 2.2.2 was both dried (9 min, 700 W) and incorporated in the precursor (5 min, 700 W) using a commercially available microwave oven. In a total synthesis time of 60 min, an overall radiochemical yield of 18% (SD=5, n=7, EOS) was obtained. Radiochemical purity was always higher than 99% and specific activity always higher than 81.4 GBq/µmol (2.2 Ci/µmol). Initial brain uptake in mice was 2.19% ID (5.47% ID/g, 2 min) but decreased rapidly (0.17% ID, 0.45% ID/g (60 min)). During the first 20 min p.i., radioactivity concentration of the brain was significantly higher than that of blood demonstrating good brain entry of the tracer. Copyright © 2004 John Wiley & Sons, Ltd. [source] Synthesis and radiolabelling of [123I]-4-iodo-N-(4-(4-(2-methoxyphenyl)-piperazin-1-yl)butyl)-benzamide, a potential dopamine D3 antagonist for SPECT studiesJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 4 2003L. Staelens Abstract Schizophrenia is a devastating mental disorder characterized by relapsing psychotic episodes accompanied with emotional, professional and social decline. The classical dopamine hypothesis of schizophrenia postulates that hyperactivity of dopaminergic neurotransmission is responsible for the positive symptoms of the disorder. More exactly hyperactivity of the dopamine D3 receptor system is thought to be involved in the pathology of schizophrenia. Therefore a new 123I-labelled compound was developed which may allow in vivo visualization of the D3 receptor by SPECT. [123I]-4-iodo- N -(4-(4-(2-methoxyphenyl)-piperazin-1-yl)butyl)-benzamide was synthesized and labelled by electrophilic aromatic substitution of the tributylstannyl derrivative. The radiochemical yield was 82,85% and the specific activity was >2.96 Ci/µmol. Copyright © 2003 John Wiley & Sons, Ltd. [source] Synthesis of N, N -diethyl-4-[phenyl-(piperidin-4-ylidene)methyl]-[carboxy - 14C]benzamide, a potent , opioid receptor agonistJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 2 2003Lars Gawell Abstract The synthesis of carbon-14 labelled N,N -diethyl-4-[phenyl-(piperidin-4-ylidene)methyl]-benzamide is described. The radioisotope is introduced via an aryllithium reaction with 14CO2 to form the labelled acid, which is subsequently transformed into the amide. Copyright © 2002 John Wiley & Sons, Ltd. [source] Improved pharmacokinetics of AMG 517 through co-crystallization part 1: Comparison of two acids with corresponding amide co-crystalsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 9 2010Mary K. Stanton Abstract The dissolution and pharmacokinetics (PK) of two carboxylic acid co-crystals (cinnamic acid and benzoic acid) with the corresponding amide co-crystals (cinnamamide and benzamide) of AMG 517 were investigated. Powder and intrinsic dissolution studies were performed in fasted simulated intestinal fluid (FaSIF). Suspension formulations in 1% polyvinylpyrrolidone K25 in water were administered orally at 100,mg/kg to rats. The four co-crystals were found to have faster intrinsic and powder dissolution rates in FaSIF than the free base. This correlated with a 2.4- to 7.1-fold increase in the area under the concentration,time curve in rat PK investigations. When contrasting the acid to its corresponding amide co-crystal, cinnamamide shows improvement over cinnamic acid, while benzamide and benzoic acid perform similarly. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:3769,3778, 2010 [source] Reactions of 1,2,5-thiadiazole 1,1-dioxide derivatives with nitrogenated nucleophiles.JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 4 20031-dioxide, 4-diphenyl-, 5-thiadiazole , Addition of amines, Part , amides to Abstract The addition reactions of some amides and aromatic amines to a CN double bond of 3,4-diphenyl-1,2,5-thiadiazole 1,1-dioxide (1) were studied in aprotic solvent solutions [N,N -dimethylformamide (DMF) and acetonitrile (MeCN)]. Equilibrium constants for the reactions of 1 with acetamide, 2-fluoroacetamide, butyramide, benzamide, aniline and 3-aminopyridine were measured using a previously reported cyclic voltammetric (CV) method. Aliphatic amines gave unstable solutions, probably owing to reactions of anionic species derived from 1. Other N nucleophiles tested (formamide, succinimide, thioacetamide and cyanamide) yielded different products that have not yet been characterized. DMF, N,N -dimethylacetamide (DMA) and N -methylacetamide did not react. The addition thiadiazoline produced in the reaction of acetamide with 1 was characterized by IR and 1H and 13C RMN NMR spectroscopy as a prototype compound. For this system, the equilibrium constant could also be measured by a standard UV,VIS method and was found to be in agreement with the value obtained by CV. The reaction of 1 with urea produced a bicyclic product, identified as 3a,6a-diphenyltetrahydroimidazo[4,5- c]-1,2,5-thiadiazol-5-one 2,2-dioxide. Copyright © 2003 John Wiley & Sons, Ltd. [source] A variety of poly(m -benzamide)s with low polydispersities from inductive effect-assisted chain-growth polycondensationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 17 2006Tomoyuki Ohishi Abstract Chain-growth polycondensation of 3-(alkylamino)benzoic acid alkyl esters 1 was investigated for obtaining poly(m -benzamide)s with defined molecular weights and low polydispersities. Polymerization conditions were first studied to find that ethyl 3-(octylamino)benzoate (1b) polymerized in a chain polymerization manner in the presence of lithium 1,1,1,3,3,3-hexamethyldisilazide (LiHMDS) as a base and phenyl 4-methylbenzoate (2b) as an initiator in THF at 0 °C. The molecular weight of the polymer was controlled by the feed ratio of monomer to initiator. The polymerization of 1c,i with a variety of N -alkyl groups was then carried out under the established conditions to yield well-defined poly(m -benzamide)s, which showed higher solubility than those of the corresponding poly(p -benzamide)s. Furthermore, the 4-octyloxybenzyl group on the amide nitrogen in poly1i was removed by treatment with trifluoroacetic acid (TFA) to give N -unsubstituted poly(m -benzamide) (poly1j) with a low polydispersity, which is soluble in DMAc and DMSO, contrary to the para-substituted counterpart. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4990,5003, 2006 [source] Vibrational spectroscopic studies and DFT calculations of 4-fluoro- N -(2-hydroxy-4-nitrophenyl)benzamideJOURNAL OF RAMAN SPECTROSCOPY, Issue 12 2008L. Ushakumari Abstract Fourier transform infrared (FT-IR) and FT-Raman spectra of 4-fluoro- N -(2-hydroxy-4-nitrophenyl)benzamide were recorded and analyzed. The vibrational wavenumbers and corresponding vibrational assignments were examined theoretically using the Gaussian03 set of quantum chemistry codes. The red-shift of the NH-stretching wavenumber in the infrared (IR) spectrum from the computed wavenumber indicates the weakening of the NH bond resulting in proton transfer to the neighboring oxygen atom. The simultaneous IR and Raman activation of the CO-stretching mode gives the charge transfer interaction through a ,-conjugated path. Copyright © 2008 John Wiley & Sons, Ltd. [source] Novel Water-Soluble Poly(m -benzamide)s: Precision Synthesis and Thermosensitivity in Aqueous SolutionMACROMOLECULAR RAPID COMMUNICATIONS, Issue 9 2006Ryuji Sugi Abstract Summary: Chain-growth polycondensations of 3-aminobenzoic acid methyl esters 1a and 1b, bearing a tri- or tetra(ethylene glycol) methyl ether unit on the amino group, respectively, were carried out with lithium hexamethyldisilazide (LiHMDS) as a base and phenyl 4-methylbenzoate (2) as an initiator in THF at 0,°C. The poly(m -benzamide)s obtained in the presence of N,N,N,,N,-tetramethylethylenediamine (TMEDA) possessed narrow molecular weight distributions (,<,1.2) with molecular weights that were determined by the feed ratios of [1]0/[2]0. Poly1a and poly1b were each soluble in water and exhibited a lower critical solution temperature (LCST) in water. Furthermore, the phase separation in water depended on the length of the oligo(ethylene glycol) side chain and on the molecular weight and molecular weight distribution of poly1. Thermally sensitive water-soluble poly(m -benzamide)s. [source] Synthesis of well-defined poly(p -benzamide) from chain-growth polycondensation and its application to block copolymersMACROMOLECULAR SYMPOSIA, Issue 1 2003Tsutomu Yokozawa Abstract Poly(p -benzamide) with a defined molecular weight and a low polydispersity and block copolymers containing this well-defined aramide was synthesized. Phenyl 4-(4-octyloxybenzylamino)benzoate (1b) polymerized at room temperature in the presence of base and phenyl 4-nitrobenzoate (2a) as an initiator in a chain-growth polycondensation manner to give well-defined aromatic polyamides having the 4-octyloxybenzyl groups as a protecting group on nitrogen in an amide. It was confirmed by a model reaction that deprotection of this protecting group proceeded completely with trifluoroacetic acid (TFA) without breaking the amide linkage. The utility of this approach to poly(p -benzamide) with a low polydispersity was demonstrated by the synthesis of block copolymers of poly(p -benzamide) and poly(N -octyl- p -benzamide) or poly(ethylene glycol). The SEM images of the supramolecular assemblies of the former block copolymer showed ,m-sized bundles and aggregates of flake structures. [source] The effect of mosapride citrate on proximal and distal colonic motor function in the guinea-pig in vitroNEUROGASTROENTEROLOGY & MOTILITY, Issue 2 2008H. S. Kim Abstract, Mosapride citrate (mosapride), a substituted benzamide, is a selective 5-HT4 receptor agonist, and is known to have prokinetic properties on the stomach. However, it is unclear whether mosapride also has a prokinetic effect on the colon. We previously found that mosapride significantly shortened colonic transit time in the guinea-pig, an animal with a distribution of colonic 5-HT4 receptors similar to that of a human. So, we aimed to separately evaluate the effect of mosapride on proximal and distal colonic motor function in the guinea-pig. Proximal (approximately 8 cm from the ileocolic junction) and distal colon (approximately 8 cm from the anus) were removed. Both ends of the colon were connected to a chamber containing a Krebs-Henseleit solution. To measure colonic transit time, artificial faeces were inserted into the oral side of the lumen and moved towards the anal side by intraluminal perfusion via a peristaltic pump. A total of 6 cm of transit was observed and time was measured in 2 cm increments. A tissue bath study, using electrical stimulation, was performed to estimate the contractile activity of the circular musculature of the colon. Immunohistochemical staining for 5-HT4 receptors was performed in the myenteric plexus and circular muscle in both proximal and distal colon, and the stained area was measured using a microscope and computer software. Mosapride enhanced contraction at 10,9 to 10,7 mol L,1, coinciding with rapid transit both in proximal and distal colon. This pattern was more prominent in proximal colon. At the high dose (10,6 mol L,1) mosapride had little or no effect on colonic contraction. This stimulatory effect was attenuated by GR113808, atropine and tetrodotoxin. In the myenteric plexus, the density of 5-HT4 receptors was significantly greater in the proximal colon than in the distal colon, but in circular muscle the density was greater in the distal colon. Thus, mosapride accelerates transit through increased contraction in the proximal colon more than distal colon. The different distribution of neuronal and muscular 5-HT4 receptors may support these findings. Therefore, mosapride may be a useful alternative to tegaserod and cisapride for constipation. [source] Gas-phase formation of protonated benzene during collision-induced dissociation of certain protonated mono-substituted aromatic molecules produced in electrospray ionizationRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 11 2010Min Li Protonated benzene, C6H, has been studied extensively to understand the structure and energy of a protonated organic molecule in the gas phase. The formation of C6H is either through direct protonation of benzene, i.e., chemical ionization, or through fragmentation of certain radical cations produced from electron ionization or photon ionization. We report a novel observation of C6H as a product ion formed in the collision-induced dissociation (CID) of protonated benzamide and related molecules produced via electrospray ionization (ESI). The formation of C6H from these even-electron precursor ions during the CID process, which has not been previously reported, is proposed to occur from the protonated molecules via a proton migration in a five-membered ring intermediate followed by the cleavage of the mono-substituent CC bond and concurrent formation of an ion-molecule complex. This unique mechanism has been scrutinized by examining some deuterated molecules and a series of structurally related model compounds. This finding provides a convenient mean to generate C6H, a reactive intermediate of considerable interest, for further physical or chemical investigation. Further studies indicate that the occurrence of C6H in liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) appears to be a rather common phenomenon for many compounds that contain ,benzoyl-type' moieties. Hence, the observation of the C6H ion in LC/ESI-MS/MS can be used as an informative fragmentation pathway which should facilitate the identification of a great number of compounds containing the ,benzoyl-type' and similar structural features. These compounds are frequently present in food and pharmaceutical products as leachable impurities that require strict control and rapid elucidation of their identities. Copyright © 2010 John Wiley & Sons, Ltd. [source] A structural systematic study of four isomers of difluoro- N -(3-pyridyl)benzamideACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2009Joyce McMahon The four isomers 2,4-, (I), 2,5-, (II), 3,4-, (III), and 3,5-difluoro- N -(3-pyridyl)benzamide, (IV), all with formula C12H8F2N2O, display molecular similarity, with interplanar angles between the C6/C5N rings ranging from 2.94,(11)° in (IV) to 4.48,(18)° in (I), although the amide group is twisted from either plane by 18.0,(2),27.3,(3)°. Compounds (I) and (II) are isostructural but are not isomorphous. Intermolecular N,H...O=C interactions form one-dimensional C(4) chains along [010]. The only other significant interaction is C,H...F. The pyridyl (py) N atom does not participate in hydrogen bonding; the closest H...Npy contact is 2.71,Å in (I) and 2.69,Å in (II). Packing of pairs of one-dimensional chains in a herring-bone fashion occurs via,-stacking interactions. Compounds (III) and (IV) are essentially isomorphous (their a and b unit-cell lengths differ by 9%, due mainly to 3,4-F2 and 3,5-F2 substitution patterns in the arene ring) and are quasi-isostructural. In (III), benzene rotational disorder is present, with the meta F atom occupying both 3- and 5-F positions with site occupancies of 0.809,(4) and 0.191,(4), respectively. The N,H...Npy intermolecular interactions dominate as C(5) chains in tandem with C,H...Npy interactions. C,H...O=C interactions form R22(8) rings about inversion centres, and there are ,,, stacks about inversion centres, all combining to form a three-dimensional network. By contrast, (IV) has no strong hydrogen bonds; the N,H...Npy interaction is 0.3,Å longer than in (III). The carbonyl O atom participates only in weak interactions and is surrounded in a square-pyramidal contact geometry with two intramolecular and three intermolecular C,H...O=C interactions. Compounds (III) and (IV) are interesting examples of two isomers with similar unit-cell parameters and gross packing but which display quite different intermolecular interactions at the primary level due to subtle packing differences at the atom/group/ring level arising from differences in the peripheral ring-substitution patterns. [source] A structural systematic study of three isomers of difluoro- N -(4-pyridyl)benzamideACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2008Joyce McMahon The isomers 2,3-, (I), 2,4-, (II), and 2,5-difluoro- N -(4-pyridyl)benzamide, (III), all with formula C12H8F2N2O, all exhibit intramolecular C,H...O=C and N,H...F contacts [both with S(6) motifs]. In (I), intermolecular N,H...O=C interactions form one-dimensional chains along [010] [N...O = 3.0181,(16),Å], with weaker C,H...N interactions linking the chains into sheets parallel to the [001] plane, further linked into pairs via C,H...F contacts about inversion centres; a three-dimensional herring-bone network forms via C,H...,(py) (py is pyridyl) interactions. In (II), weak aromatic C,H...N(py) interactions form one-dimensional zigzag chains along [001]; no other interactions with H...N/O/F < 2.50,Å are present, apart from long N/C,H...O=C and C,H...F contacts. In (III), N,H...N(py) interactions form one-dimensional zigzag chains [as C(6) chains] along [010] augmented by a myriad of weak C,H...,(arene) and O=C...O=C interactions and C,H...O/N/F contacts. Compound (III) is isomorphous with the parent N -(4-pyridyl)benzamide [Noveron, Lah, Del Sesto, Arif, Miller & Stang (2002). J. Am. Chem. Soc.124, 6613,6625] and the three 2/3/4-fluoro- N -(4-pyridyl)benzamides [Donnelly, Gallagher & Lough (2008). Acta Cryst. C64, o335,o340]. The study expands our series of fluoro(pyridyl)benzamides and augments our understanding of the competition between strong hydrogen-bond formation and weaker influences on crystal packing. [source] Research Letter: New Potent Indole Derivatives as Hyaluronidase InhibitorsCHEMICAL BIOLOGY & DRUG DESIGN, Issue 6 2007Süreyya Ölgen Because of the physiologic importance of hyaluronidases, the identification of potent and selective inhibitors of hyaluronidases has become increasingly important. A variety of assay methods have been used for such a purpose, i.e. classical turbidimetric, viscometric and colorimetric. In this study, a modified enzymatic assay has been used to obtain a microtiter plate-based sensitive activity screening. All inhibitors were tested in a stains-all assay at pH 7 and in a Morgan-Elson assay at pH 3.5. Among the tested compounds, 1, 2, 3, 6, 7, 8, 16, 17 and 18 showed good inhibition of more than 50%, so the IC50 values of these derivatives were determined in the range of 25,41 ,m. The IC50 value of the most active hyaluronidase inhibitor Vcpal (6-palmitoyl- l -ascorbic acid) was measured as 8.36 ,m. All inhibitors including Vcpal showed twofold less activity at pH 3.5 in a Morgan-Elson assay. Examination of substituent effects on the activity showed that para -positions of benzamide needs to be chlorinated or fluorinated to obtain good inhibitory effect. It was found that the introduction of a p -fluoro benzyl ring in the indole nitrogen has a positive effect for the inhibitory effects of both indole-2- and 3-carboxamide derivatives. [source] Transformation of N-(5-Acetyl-6-methyl-2-oxo-2H-pyran-3-yl)benzamide with Hydrazines in the Presence of an Acidic Catalyst.CHEMINFORM, Issue 18 2004Lidija Vranicar Abstract For Abstract see ChemInform Abstract in Full Text. [source] Self-Association of Bis-Dendritic Organogelators: The Effect of Dendritic Architecture on Multivalent Cooperative InteractionsCHEMISTRY - A EUROPEAN JOURNAL, Issue 8 2010Myungeun Seo Dr. Abstract A series of bis-dendritic gelators consisting of a benzamide dendron and an alkyl dendron were synthesized to investigate the dendritic effect on self-assembly. The gelators with a first-generation benzamide (benzamide- G1) dendron or a first-generation alkyl (alkyl- G1) dendron formed stable gels in most aromatic solvents, and their self-assembled fibrillar networks were imaged by electron microscopy. The unbranched molecule (G0 - G0) or the molecule possessing a second-generation benzamide (benzamide- G2) dendron did not form gels. Differential scanning calorimetry, powder X-ray diffraction, and Fourier transform IR studies revealed that introduction of a dendritic branch strongly affected the molecular packing as well as the strength of intermolecular interactions. Furthermore, concentration-dependent diffusion coefficient measurements and the evaluation of association constants by 1H NMR spectroscopy indicated that bis-dendritic gelators with a benzamide- G1 dendron possessed high association constants and formed large aggregates, whereas molecules with a single benzamide formed dimers in chloroform. The formation of self-assembled fibrillar networks was driven by the multivalent and cooperative hydrogen bonding observed in the benzamide- G1 dendrons. ,,, stacking of aromatic groups and van der Waals interactions between alkyl chains also played roles in the self-assembly process, thus indicating that a spatial balance between two dendrons is important. [source] Lewis Base Catalyzed Mannich-Type Reactions between Trimethylsilyl Enol Ethers and AldiminesCHEMISTRY - A EUROPEAN JOURNAL, Issue 19 2006Hidehiko Fujisawa Abstract Lewis base catalyzed Mannich-type reaction between trimethylsilyl enol ethers and N -tosylaldimines is described. Nitrogen anions generated from amides or imides such as lithium benzamide or potassium phthalimide are found to be effective Lewis base catalysts in DMF at room temperature to afford the corresponding ,-amino carbonyl compounds in good to high yields; the oxygen anion generated from carboxylic acids such as lithium acetate was also found to be effective in dry DMF. The above-mentioned lithium acetate-catalyzed Mannich-type reaction between aldimines and various trimethylsilyl (TMS) enol ethers such as silyl ketene acetal proceeded smoothly even in water-containing DMF. Then, Lewis base catalyzed three-component Mannich-type reactions of TMS enol ether, tosylamide, and aromatic aldehyde having electron-withdrawing group such as p -nitrobenzaldehyde were investigated. The reaction proceeded smoothly to afford the corresponding ,-amino ester in good yield. Further, ammonium carboxylates such as tetrabutyl ammonium acetate or tetrabutyl ammonium benzoate were found to be more effective Lewis base catalysts in the above-mentioned Mannich-type reaction. The synthesis proceeded in various solvents at lower temperatures. The reaction between aldimines and TMS enol ethers generated from thioester and various ketones such as propiophenone or cyclohexanone also proceeded smoothly to afford the corresponding ,-amino carbonyl compounds in high yields with good to high anti -selectivities. [source] Variable-Temperature Powder X-ray Diffraction of Aromatic Carboxylic Acid and Carboxamide CocrystalsCHEMISTRY - AN ASIAN JOURNAL, Issue 4 2007L. Sreenivas Reddy Abstract The effect of temperature on the cocrystallization of benzoic acid (BA), pentafluorobenzoic acid (FBA), benzamide (BAm), and pentafluorobenzamide (FBAm) is examined in the solid state. BA and FBA formed a 1:1 complex 1 at ambient temperature by grinding with a mortar and pestle. Grinding FBA and BAm together resulted in partial conversion into the 1:1 adduct 2 at 28,°C and complete transformation into the product cocrystal at 78,°C. Further heating (80,100,°C) and then cooling to room temperature gave a different powder pattern from that of 2. BAm and FBAm hardly reacted at ambient temperature, but they afforded the 1:1 cocrystal 3 by melt cocrystallization at 110,115,°C. Both BA+FBAm (4) and BA+BAm (5) reacted to give new crystalline phases upon heating, but the structures of these products could not be determined owing to a lack of diffraction-quality single crystals. The stronger COOH and CONH2 hydrogen-bonding groups of FBA and FBAm yielded the equimolar cocrystal 6 at room temperature, and heating of these solids to 90,100,°C gave a new crystalline phase. The X-ray crystal structures of 1, 2, 3, and 6 are sustained by the acid,acid/amide,amide homosynthons or acid,amide heterosynthon, with additional stabilization from phenyl,perfluorophenyl stacking in 1 and 3. The temperature required for complete transformation into the cocrystal was monitored by in,situ variable-temperature powder X-ray diffraction (VT-PXRD), and formation of the cocrystal was confirmed by matching the experimental peak profile with the simulated diffraction pattern. The reactivity of H-bonding groups and the temperature for cocrystallization are in good agreement with the donor and acceptor strengths of the COOH and CONH2 groups. It was necessary to determine the exact temperature range for quantitative cocrystallization in each case because excessive heating caused undesirable phase transitions. [source] An Unusual N -Boc Deprotection of Benzamides under Basic ConditionsCHINESE JOURNAL OF CHEMISTRY, Issue 9 2009Biaolin Yin Abstract For the first time, an unusal cleavage of N-tert -butyloxycarbonyl (N -Boc) protection from N -Boc-protected benzamide under basic conditions in excellent yields is reported. The deprotection involves the N -Boc emigration from the benzamide to form 2- O -Boc group followed by O -Boc deprotection on the phenyl ring. [source] Product Selectivity Control in the Heteroannulation of o -(1-Alkynyl)benzamidesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1 2010Gabriele Bianchi Abstract The selective synthesis of (Z)- or (E)-3-aryl/vinyl/alkylidene-isoindolones, and 2-benzopyran derivatives from o -(1-alkynyl)benzamides by means of a suitable choice of bases or silver catalysis is described. [source] Silver-Catalyzed Intramolecular Cyclization of o -(1-Alkynyl)benzamides: Efficient Synthesis of (1H)-Isochromen-1-iminesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2009Guannan Liu Abstract An efficient avenue for the facile and atom-economic synthesis of (1H)-isochromen-1-imines has been developed, and a broad spectrum of substrates can participate in the process effectively to produce the desired products in good yields. Significantly, this is the first report of the synthesis of (1H)-isochromen-1-imines that involves a silver(I)-catalyzed, regiocontrolled intramolecular addition of the carbonyl group of the amide moiety towards an alkyne. [source] Anionic Bridged Bis(amidinate) Lithium Lanthanide Complexes: Efficient Bimetallic Catalysts for Mild Amidation of Aldehydes with AminesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009Junfeng Wang Abstract Anionic bridged bis(amidinate) lithium lanthanide complexes have been found to be efficient catalysts for the amidation of aldehydes with amines under mild conditions. The activity follows the order: yttrium
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