Modification of carbon nanofibres for the immobilization of metal complexes: a case study with rhodium and anthranilic acid

The immobilisation of the rhodium/anthranilic acid complex onto fishbone carbon nanofibres (CNFs) was executed by means of the following steps: 1) surface oxidation of the fibres, 2) conversion of the oxygen-containing surface groups into acid chloride groups, 3) attachment of anthranilic acid and 4) complexation of rhodium by the attached anthranilic acid. The immobilisation process was followed and the resulting surface species were characterised by IR, X-ray absorption fine structure (XAFS) and X-ray photoelectron spectroscopy (XPS), and by molecular modelling. Anthranilic acid bonds to the CNFs by an amide linkage to the carboxyl groups that are present after surface oxidation of the fibres. The immobilised anthranilic acid coordinates to rhodium through the nitrogen atom and the carboxyl group. The assynthesised RhIII complex itself is not active in the liquid-phase hydrogenation of cyclohexene. Reduction with sodium borohydride yields small particles (d = 1.5-2 nm) of rhodium metal that are highly active. The results indicate that different activation procedures for the immobilised Rh/anthranilic acid system should be applied, such as reduction with a milder reducing agent or direct complexation of the rhodium in the RhI state.     

Palladium-catalyzed mono-N-allylation of unprotected anthranilic acids with allylic alcohols in aqueous media

Palladium-catalyzed N-allylation of anthranilic acids 1a-j with allyl alcohol 2a in the presence of Pd(OAc)(2), sodium diphenylphosphinobenzene-3-sulfonate (TPPMS) in THF-H(2)O at room temperature gave only mono-N-allylated anthranilic acids 3a-j in good yields (70-98%). The reactions of 4-bromoanthranilic acid 1i with 2-methyl-3-buten-2-ol 2b showed complete chemoselectivity in N-allylation (neutral conditions) and C-vinylation (basic conditions). In our catalytic system, the keys to success are use of an unprotected anthranilic acid as a starting material and the presence of water in the reaction medium. The carboxyl group of anthranilic acid and water may play important roles for the smooth generation of the π-allyl palladium species by activation of the hydroxyl group of the allylic alcohol.     

N-[3-nitro(amino)coumarin-4-yl]anthranilic acid amides. Synthesis of 6,7,8,13-tetrahydro[1]benzopyrano[4,3-b][1,4] benzodiazepine-6,8-dione

The reaction of 3-nitro-4-chlorocoumarin with anthranilic acid was used to synthesize N-(3-nitro-4-coumarinyl)-anthranilic acid, from which, through the acid chloride, we obtained a number of amides, which were reduced to N-(3-amino-4-coumarinyl)anthranilic acid amides The latter are cyclized under the influence of hydrochloric acid to 6,7,8,13-tetrahydro[1]benzopyrano-[4,3-b][1, 4]benzodiazepine-6,8-dione, which was also obtained from N-(3-amino-4-coumarinyl)anthranilic acid by its thermolysis or treatment with hydrochloric acid.See [1] for our preliminary communication.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1208–1212, September, 1989.     

Regioselective copper-catalyzed amination of chlorobenzoic acids: synthesis and solid-state structures of N-aryl anthranilic acid derivatives

[reaction, structure: see text] A chemo- and regioselective copper-catalyzed cross-coupling reaction for effective amination of 2-chlorobenzoic acids with aniline derivatives has been developed. The method eliminates the need for acid protection and produces a wide range of N-aryl anthranilic acid derivatives in up to 99% yield. The amination was found to proceed with both electron-rich and electron-deficient aryl chlorides and anilines and also utilizes sterically hindered anilines such as 2,6-dimethylaniline and 2-tert-butylaniline. The conformational isomerism of appropriately substituted N-aryl anthranilic acids has been investigated in the solid state. Crystallographic analysis of seven anthranilic acid derivatives showed formation of two distinct supramolecular architectures exhibiting trans-anti and unprecedented trans-syn dimeric structures.     

Photochemical behavior of lanthanide-containing polymer materials

Light-transforming polymer materials activated by compositions based on the mixed-ligand europium carboxylates and anthranilic acid exhibiting an intense luminescence in the spectral region 400–700 nm are prepared. The photolysis of the polymer materials is investigated. For the obtained compositions the flaring of intensity of luminescence of europium ion and anthranilic acid was detected.     

Ultrasonic irradiation of the ullmann condensation: Application to the preparation of dioxolo,dioxino, cyclopent,and imidazolo anthranilic acid derivatives

The synthesis of N‐aryl anthranilic acid derivatives bearing dioxolo, dioxino, cyclopent, and imidazolo supplementary ring systems is reported. The Ullmann‐Goldberg condensation of the N‐aryl anthranilic acid is improved in yield and reaction time, compared to conventional heating; by ultrasonic irradiation.     

NMR and photo-CIDNP investigations of the glycyrrhizinic acid micelles influence on solubilized molecules

It was found that photolysis of N-acyl anthranilic acid methyl ester is very sensitive to solvent nature. This sensitivity was connected with the equilibrium between intramolecular and intermolecular hydrogen bonding. Also it has been established the glycyrrhizinic acid micelle formation in water-methanol mixture with CMC about 0.5–1 mM. Solubilization of N-acyl anthranilic acid methyl ester in glycyrrhizinic acid micelles decreases photoreaction efficiency comparing with the homogeneous solvent.     

The luminescent properties of polyethylene films with admixtures of luminophores based on europium compounds

Polyethylene films activated with europium(III) complexes with carboxylic acids and Eu(L)₃ · nD · xH₂O + ANT compositions, where L is the trifluoroacetic, toluyl, or cinnamic acid anion and ANT is anthranilic acid, were prepared. The intensity of luminescence of the polymeric compositions depended on the content of luminophores (molar ratio between europium compounds and anthranilic acid). An analysis of the excitation spectra showed that, in polymer—Eu(L)₃ · nPhen · xH₂O + ANT compositions, there was effective energy transfer from phenanthroline to anthranilic acid levels.     

Polymerization of aniline derivatives by K2Cr2O7 and production of Cr2O3 nanoparticles

Oxidative polymerization of aniline, anthranilic acid, and aniline‐co‐anthranilic acid by potassium dichromate Cr(VI) as an oxidant in acidic medium was investigated. In this study, the polymerization process of aniline, o‐anthranilic acid as well as aniline/o‐anthranlic acid using K₂Cr₂O₇ produced, coordinated Cr(III)/polyaniline (PANI), Cr(III)/polyanthranilic acid (PAA) and Cr(III)/poly aniline‐co‐anthranilic acid (PANAA). The mechanism of polymerization reaction in the presence of dichromate was hypothesized. The precursor chromium doped polymers were characterized by TGA, FT‐IR, UV‐visible, XRD analyses. Cr₂O₃ nanoparticles size were determined using TEM analysis. The calcinations process of synthesized chromium doped PANI, PAA and PANAA yields Cr₂O₃ nanoparticles 26%, 31%, and 34% wt. respectively. Rhombohedral phase of Cr₂O₃ particles in the range from 33 to 61 nm was produced from chromium/polyanthranilic acid (PAA) and chromium/poly(aniline‐co‐anthranilic acid) PANAA. UV‐ visible analysis showed that optical band gaps (E_g) of doped poly aniline and its derivatives are in the range from1.55 to 1.80 using Tacu's law. The band gap values reveal that the doped chromium emeraldine base can be used as semiconductor materials. Copyright © 2016 John Wiley & Sons, Ltd.     

Regioselective copper-catalyzed amination of bromobenzoic acids using aliphatic and aromatic amines

A chemo- and regioselective copper-catalyzed cross-coupling procedure for amination of 2-bromobenzoic acids is described. The method eliminates the need for acid protection and produces N-aryl and N-alkyl anthranilic acid derivatives in up to 99% yield. N-(1-Pyrene)anthranilic acid has been employed in metal ion-selective fluorosensing. Titration experiments showed that this pyrene-derived amino acid forms an equimolar complex with Hg(II) in water resulting in selective fluorescence quenching even in the presence of other metal ions such as Zn(II) and Cd(II).     

Oxidative ring opening of 3-hydroxyquinoline-2,4(1H,3H)-diones into N-(α-ketoacyl)anthranilic acids

N-(α-Ketoacyl)anthranilic acids were prepared by oxidative ring opening of 3-hydroxyquinoline-2,4(1H,3H)-diones by using paraperiodic acid (H₅IO₆) or sodium periodate (NaIO₄). The optimisation of the reaction conditions is described as well as the utilisation of N-(α-ketoacyl)anthranilic acids in the preparation of anthranilic acid hydrochlorides.     

Exploitation of electrostatic field force for immobilization and catalytic reduction of o-nitrobenzoic acid to anthranilic acid on resin-bound silver nanocomposites

A new solid-phase catalyst has been designed and reported here for the catalytic reduction of o-nitrobenzoic acid to anthranilic acid. Electrostatic field force helps immobilization, in turn deposition of silver nanoparticles onto solid resin surfaces and reduction of o-nitrobenzoic acid through effective catalysis. While characterization of catalyst particles has been performed by different physical methods (XRD, XPS, SEM, TEM, and EDX) in a worthwhile fashion, selective reduction of o-nitrobenzoic acid has also been achieved conveniently (approximately 95%). Different thermodynamic parameters for the reduction reaction have been presented from varied experimental conditions. Novelty of this work lies with the catalytic efficiency of nanometer size silver particles immobilized solid-phase matrix for one step synthesis of anthranilic acid over bulk silver.     

Iridium-catalyzed direct ortho-C–H amidation of benzoic acids with sulfonylazides

A mild and efficient iridium-catalyzed ortho-C–H amidation with sulfonyl azides by weakly coordinating carboxylic acid was demonstrated, which provided a novel approach to anthranilic acid derivatives.     

Pyrimidines LXI. Synthesis of N-pyrimidinylanthranilic acids and 2, 4-diarylpyrimido[2,1-b]quinazol-6-ones

N-(4,6-Diarylpyrimidinyl)anthranilic acids, obtained by condensation of the appropriate 2-chloropyrimidines with anthranilic acid, are converted to 2,4-diarylpyrimido[2,1-b] quinazol-6-ones when they are treated with acetic anhydride.See [1] for communication LX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 678–683, May, 1977.     

Reaction of anthranilic acid 2-<Emphasis Type="Italic">N</Emphasis>-phenylhydrazide with cyclic anhydrides

In the reaction with cyclic anhydrides the anthranilic acid 2-N-phenylhydrazide depending on conditions yielded either anthranilic acid 2-N-acyl-2-N′-phenylhydrazides, 2-R-3-anilinoquinazolin-4(3H)-ones, or derivatives of 1-phenylpyridazino[3,2-b]quinazoline-2,10-dione.     

2-Bis(carboxymethyl)-amino-5-hydroxy-terephthalsäure als ambifunktioneller Ligand in Eisen(III)-Komplexen

2-Bis(carboxymethyl)-amino-5-hydroxy-terephthalic Acid as an Ambifunctional Ligand in Iron(III) Complexes From steric reasons the anthranilic acid -N,N-diacetic acid group and the salicylic acid group of 2-bis(carboxymethyl)-amino-5-hydroxy-terephthalic acid (H₅C) cannot coordinate to the same central atom. With iron(III) H₅C forms the mononuclear complex (HC)Fe(OH)^2?, the central atom is fixed to the anthranilic acid N,N-diacetic acid group. In a weak acid medium (HC)Fe(OH)^2? is converted into the binuclear species (HC)Fe(C)Fe(OH)^4? which is of a deep red colour. In this complex the anion C^5?has the function of a bridging ligand coordinating both by the anthranilic acid-N,N-diacetic acid group and by the salicylic acid group. The complex formation in the ternary system iron(III)/nitrilo triacetic acid/5-sulfo salicylic acid may be used as model for the dimerisation of the anion (HC)Fe(OH)^2?.     

Reactions of diarylamines with hexafluoroacetone

Diphenylamine reacts with hexafluoroacetone to give a mixture of products, of which 2-(1-hydroxy-1-trifluoromethyl-2,2,2-trifluoroethyl)diphenylamine (II) was isolated. N-Arylanthranilic acids modify the 1,1,1,3,3,3-hexafluoro-2-hydroxy-2-propyl group upon the reaction of its sodium salt with the hydrate of hexafluoroacetone (I) under mild conditions. This method gave 4-(1-hydroxy-1-trifluoromethyl-2,2,3-trifluoroethyl)-N-(2,3-xylyl)anthranilic acid from N-(2,3-xylyl)anthranilic acid in 93% yield.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 952–954, April, 1991.     

4(3H)-喹唑啉酮类Schiff碱的合成与抗烟草花叶病毒活性

采用邻氨基苯甲酸经醋酐酰化闭环得2-甲基苯并噁嗪-4-酮, 水合肼回流合成2-甲基-3-氨基-4(3H)-喹唑啉酮, 在无水乙醇中与芳醛反应得4(3H)-喹唑啉酮类Schiff碱. 经元素分析, IR, 1H NMR, 13C NMR对所合成的化合物进行了结构确认和表征. 初步生物活性测试表明, 化合物3t具有较高的抗烟草花叶病毒活性.     

Condensed isoquinolines 23. Reaction of <Emphasis Type="Italic">o</Emphasis>-bromomethylphenyl-acetonitrile with anthranilic acids: Synthesis of 6H, 12H,17H-dibenzo[3,4:6,7][1,8]-naphthyridino[1,8-<Emphasis Type="Italic">ab</Emphasis>]quinazoline-6,17-diones

The direction of the reaction of anthranilic acids with o-bromomethylphenylacetonitrile upon fusion depends on the temperature and nature of the substituent in the anthranilic acid. The reaction may lead to three types of products: Derivatives of 7,12-dihydro-5H-isoquino[2,3-a]quinazolin-5-ones below 150°C and to 6,11-dihydro-13H-isoquino[3,2-b]quinazolin-13-one or derivatives of 6H,12H,17H-dibenzo[3,4:6,7][1,8]naphthyridino[1,8-ab]quinazoline-6,17-diones above 150°C depending on the nature of the substituent in the anthranilic acid. A study was carried out on the mechanism for the formation of 6H,12H,17H-dibenzo[3,4:6,7][1,8]naphthyridino[1,8-ab]quinazoline-6,17-diones, which permitted the preparation of 6-(4-methylphenyl)-6,12-dihydro-5H-isoquino[2,3-a]quinazolin-5-one. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1059–1067, July, 2007.     

The determination of small quantities of metal ions using anthranilic acid

Metal ions which form insoluble anthranilates may, if present singly, be determined by dissolving the anthranilate in acid and titrating the liberated anthianilic acid with perchloratocerate. Or preferably the anthranilic acid may be determined absorptiometrically with N-(1-naphthyl) ethylenediamine hydrochloride after diazotisation. Under the conditions described quantities of the order of 1–5 micromoles of metal are conveniently determined by the volumetric method and one fifth of such amounts by absorptiometry. With the latter the use of larger Spekker cells would increase the sensitivity of the method.By making use of the insolubility of its complex in acetate buffers copper may be determined in the presence of other metals if these are not in excessive amounts. Various other determinations. are also possible.Attempts to use the fluorescence of the liberated anthranilic acid have indicated the method to be less satisfactory than absorptiometry.