Amide Type Research Articles

Extraction of Americium(III) and Europium(III) with Two Open-Chain Crown Ethers of Amide Type

The extraction of Am3+ and Eu3+ from aqueous picric acid solution by N, N′-dinaphthyl-N, N′-diphenyl-3,6-dioxaoctanediamide (LI) and 1, 1′-(3, 6, 9-trioxaundecanedionyl)diphenothiazine (LII) was investigated by a radioactive tracer technique. Extraction distribution ratios of Am3+ and Eu3+ have been measured as a function of pH, picric acid concentration, extractant concentration, diluent and temperature. The extraction of Am3+ is preferred to that of Eu3+ for both LI and LII, and the latter gives larger separation factor than the former. The equilibrium constants and thermodynamic parameters of extraction reactions were also calculated.

Amide-Based Oligocatenanes by an Iterative Template Strategy

A new pathway for the supramolecular synthesis of oligocatenanes is developed. It is based on a combination of most suitable macrocyclic structural units, obtained from tert-butyl-substituted isophthalic acid and terephthalic acid building blocks. These structural parts guarantee, on the one hand, the solubility of the catenanes and their intermediates, and, on the other hand, the preferred formation of larger ring sizes of the macrocycles to be intertwined. Acting as monotopic and ditopic concave templates, the tetra- and octalactam macrocycles were submitted to threading procedures to yield higher-order catenanes of the amide type. By repetition of the threading steps, it was possible to isolate multiply mechanically connected [n]catenanes up to n=4 composed of various macrocyclic units.

Dication C(R 1)–N(R 2) 2 Synthons and their use in the Synthesis of Formamidines, Amidines, and α-Aminonitriles

A combination of amides and 2-pyridinesulfonyl chloride was evaluated as synthons of the dication C(R 1)–N(R 2) 2 2+. When the substrates were primary amines, high yields of formamidines and amidines were obtained. When the substrates were α-aminoamides, α-aminonitriles were obtained. Through this process, naturally occurring α-aminoacids can be transformed into chiral α-aminonitriles with complete retention of stereochemical configuration. All reactions proceed rapidly at room temperature, and normally finish within 10 min, with yields ranging from 80 to 95% for most cases. Among the sulfonyl chlorides examined, 2-pyridinesulfonyl chloride stands out in both reaction rate and selectivity of formamidine or amidine versus sulfonyl amide. The scope and limitations of the reaction among different types of amides as synthons and amines as substrates were examined.

Anaesthesia in lipid myopathy

Anaesthesia in lipid myopathy

Amide-Based [3]Catenanes and [2]Catenanes with Aliphatic Chains

[3]Catenanes of the amide type were synthesized preparatively for the first time. Large macrocycles bearing two guest-binding sites were used to synthesize these amide-linked [3]catenanes in yields of 4%, either by formation of rigid macrocyclic boxes, or with macrocycles consisting of flexible long-chained aliphatic diamines. Furthermore, the systematic introduction of 1,ω-alkane diamines as building blocks for catenanes is described. The synthesis of a series of [2]catenanes by varying the ring size of one of the two macrocycles was also achieved in yields of 10%.

From rotaxanes to knots. Templating, hydrogen bond patterns, and cyclochirality

Abstract Rotaxanes of the amide type have been accessible in preparative yields by a variety of reactions. Beneath SN2- and SN2t-mechanisms we developed a synthesis of [2]rotaxanes that comes off a Michael addition. The motif of the attractive interactions between an axle-shaped and a macrocyclic wheel part to form rotaxanes consists of multiple hydrogen bonds in the nonionic strategy (threading), as well as in a new high yield anionic template synthesis (trapping). We introduce new synthetic routes for the preparation of [n]rotaxanes using nonionic as well as anionic templates. Furthermore, we report on the latest results of the statistical synthesis (slipping) by melting together axle and wheel to form rotaxanes. The chiroptical properties of a homologous series of cycloenantiomeric [1]rotaxanes as well as a cyclodiastereomeric [3]rotaxane have been described. The differences in the Cotton effects obtained show that small structural changes have an impact on the chiroptical properties of rotaxanes. The first X-ray structures obtained of cycloenantiomerically chiral amide-based [2]- and [1]rotaxanes as well as of the first topologically chiral amide-based knot compound were solved which show networks of H-bonds between the entities of the rotaxanes and the segments of the knot-shaped molecule. Our investigations in template effects based on hydrogen bonding for the synthesis of supramolecular structures open up a variety of strategies for the preparation of catenanes, rotaxanes andrecentlyeven molecular knots.

Effect of exogenous NH4 +-N supply on distribution of ureide content in various tissues of alfalfa plants, Medicago sativa

The profile of ureide (allantoin and allantoic acid) accumulation in various tissues of alfalfa, Medicago sativa, was surveyed under different nitrogen nutrient conditions. In the xylem sap, the ratio of ureides to asparagine of two amide type legumes, alfalfa and Lotus corniculatus, was 14 times lower than that of a typical ureide type legume, soybean when they grew in a nitrogenfree nutrient solution. In alfalfa plants, the ureide concentration was higher in the lateral roots and in the nodules than in other tissues. In the main root the concentration of ureide increased gradually towards the root tip. This distribution of ureides, except for the nodule tissues, was similar to that of the non-nodulating soybean variety. Application of ammonium sulfate to the root system slightly increased the ureide content in various tissues of alfalfa in the short term, while the ureide content in the nodule tissues rather decreased after the treatment. The data indicated that ureide accumulation mainly occurred in roots and leaves in the case of alfalfa in the same way as in non-nodulating soybean plants, although the content was much lower than in soybean nodules.

Influence of different spacers on the mesomorphic properties of 4-biphenyl derivatives within the F-alkylated series

In order to determine the influence of modification of the shape of the connector, within the fluorinated series, on the formation of mesophases in low molecular mass compounds, we decided to examine the mesomorphic behaviour of molecules which consist of a 4-biphenyl unit linked to a fluorinated tail via different spacers. The synthesis and the physical properties of these new materials are reported. The mesomorphic properties were characterized by polarized light microscopy and by differential thermal analysis, thereby showing the peculiar contribution of each of the spacers. The data collected from the 4-biphenyl derivatives synthesized allow us not only to confirm the enhancement of the smectic properties owing to the fluorinated alkyl chains, but also to display the impact of the spacer on these properties. Actually, some spacers like the amide or thioether type, as well as that of the hemithioacetal derivatives give suppression of the smectic character. Some others like that in the esters with an OC(O) spacer lead to mesophase or a short range SmA phase, and others give rise to broad enantiotropic behaviour like that of the esters with a C(O)O spacer, and of the ether or thioester types. These last mentioned give mesomorphic behaviour over a wide temperature range.

Synthesis and properties ofpara-linked aromatic polycondensates containing 3,3′,4,4′-biphenyltetracarboxylic-N,N′-bis(4-amino-biphenyl) diimide units

Two new diamino monomers based on 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) were synthesized and used in a low temperature polyamide polycondensation. High molecular weight homopoly(amide-imide)s and copoly(amide-imide)s were synthesized via in-situ silylation and investigated with respect to their solution, thermal, and film forming properties. All polymers are soluble in strong acids and most in amide type solvents. Inherent viscosities up to 7.4 dl/g in N-methyl-2-pyrrolidone (NMP)/LiCl were achieved. A methyl substitution in ortho-position to the imide group resulted in polymers possessing improved solubility and good thermal stability up to 500°C. Isotropic films can be prepared from solution.

Mesomorphic Properties of Side-Chain type Polymers Containing Hydrogen Bonding Group

Side chain type liquid crystalline polymer(SLCP)s with a carboxylic acid or an amide group in the side chain were synthesized by radical polymerization to examine the influence of intermolecular interaction on thermal properties of the polymers. An enantiotropic smectic phase was induced for the butoxyazobenzene copolymers containing 50–60 mol% of carboxylic acid moiety, while two smectic phases were observed for amide type SLCPs with butoxy group as a mesogenic terminal group. It demonstrates that intermolecular hydrogen bonding formed between carboxylic acid groups and between each mesogenic group in the side chain plays an important role to exhibit the liquid crystalline phase by thermally controlled FT-IR measurements.

The effect of mixed surfactants on enhancing oil recovery

AbstractMicelles composed of mixed surfactants with different structures (mixed micelles) are of great theoretical and industrial interest. This work pertains tomaximizing interfacial tension (IFT) reduction via surfactant pairs. In this respect, four types of fatty acid amides based on lauric, myristic, palmitic, and stearic acids were blended with dodecyl benzene sulfonic acid at a molar ratio of 4∶1 and designated as A1, A2, A3, and A4, respectively. The IFT was measured for each blend at different concentrations using Badri crude oil. The most potent formula (A4) was evaluated for using in enhanced oil recovery (EOR). The IFT was tested in the presence of different electrolyte concentrations with different crude oils at different temperatures. Finally several runs were devoted to study the displacement of Badri crude oil by A4 surfactant solution using different slug sizes of 10, 20, and 40% of pore volume (PV). The study reveled that Badri crude oil gave ultra‐low IFT at lowest surfactant concentration and 0.5% of NaCl. The recovery factor at a slug size of 20% PV was 83% of original oil in place compared with 59% in case of conventional water flood.

Atropisomeric amides: stereoselective enolate chemistry and enantioselective synthesis via a new SmI2-mediated reduction

The use of certain types of atropisomeric amides, incorporating an N-MEM-ortho-tert-butylaniline group, for stereoselective reactions, has been explored. Enolate reactions of these systems are highly diastereocontrolled, and enantiomerically enriched starting materials can be obtained, starting from lactic acid, via a new SmI2 mediated reduction process.

High-Frequency Vibrations of the Simplest Benzylic Amide [2]Catenane

Infrared and Raman spectroscopies along with molecular orbital calculations are used to study - for the first time - the vibrational motions of a topologically complicated chemical system, namely a [2]catenane of the benzylic amide type. Because of the intrinsic line width of the spectra, comparison of experiments and theory is only partially successful. The insight given by the simulations-which show that the C=O normal modes are delocalized while the N-H modes are localized - is, however, useful and makes us propose a simple model that explains both the larger line width of the spectra of the catenane with respect to those of the parent macrocycle and the great sensitivity of the infrared spectrum of the catenane to the environment. Examples of such sensitivity are the frequency shifts observed upon going from KBr to CsI, features not present in the case of the macrocycle.

New alquil amide type cationic surfactants from arginine

The synthesis, stability, surface activity and antimicrobial properties of a new family of cationic surfactants (the long chain arginylalkylamide dihydrochloride salts) derived from the condensation of the amino acid arginine and a long chain alkylamine are described. The surface active parameters reported are c.m.c. (critical micellar concentration), pC20 (negative log of the surfactant molar concentration required to reduce the surface tension of the solvent by 20 mN m–1), γc.m.c. (the surface tension at the c.m.c.), Γmax (the maximum surface excess concentration) and Amin (the minimum area per surfactant molecule at the interface). These data and those obtained from the evaluation of the antimicrobial properties are compared with the data corresponding to another family of cationic surfactants reported earlier by our group: the long chain N α-acylarginine methyl ester salts.Moreover, the synthesis of analogues possessing a reactive group capable of bonding to wool or cotton fibres is described: the long chain Nα-dichlorotriazinylarginylalkylamide monohydrochloride salts. We expect these compounds to bond to the textile substrate by the formation of a covalent bond. Confirmation of this is, however, necessary.

Hydrogen bonds in the adduct of 1,8-bis(N,N-dimethylamino)naphthalene (DMAN) with 4-(p-nitrophenyl)disic acid (NPDA)

The structure and IR spectra of the 1:1 ionic adduct of 1,8-bis(dimethylamino)-naphthalene (DMAN) with 4-(p-nitrophenyl)disic acid (NPDA) were studied. The adduct crystallises in a triclinic system, space group Pl̄, a = 9.066(2), b = 10.156(2), c = 12.716(3) A ̊ , α = 99.02(2), β = 107.84(3), γ = 100,46(3)°, Z = 2. In the protonated DMAN the [NHN] + hydrogen bridge of 2.586(2) Å length is close to symmetric with the v NHN stretching vibration band located in the region 300–700 cm −1. The NPDA deprotonated molecules form centrosymmetric dimeric anions with the amide type NH·O hydrogen bonds of 2.827(2) Å length. The negative charge of the anionic units is largely diffused over the nitrophenyl groups. The IR spectrum confirms medium strong NH·O hydrogen bonds formed in dimeric anions.

Contact Allergy and Cross-Reactions Caused by Prilocaine

Background: Allergic contact dermatitis from local amide anesthetics such as lidocaine (Xylocaine), bupivacaine (Marcaine, Bicain), mepivacaine (Carbocaine), etidocaine (Duranest), and prilocaine (Citanest) is rare. Allergic contact dermatitis from prilocaine has been reported only from EMLA cream. Objectives: We report on a patient sensitized from prilocaine used as a local infiltration anesthetic. Methods: Conventional patch testing with various local amide anesthetics as well as intracutaneous tests with amide anesthetics were performed. Results: Patch testing with EMLA cream (as is) (Astra, Sweden), containing prilocaine and lidocaine provoked an allergic patch test reaction, whereas patch testing with lidocaine was negative. Patch testing with Citanest containing 2% prilocaine and adrenaline was positive. Also articaine gave an allergic patch test reaction, whereas mepivacaine, benzocaine, and caine-mix were negative. Intracutaneous tests with prilocaine and articaine were positive. Conclusion: Our patient had been sensitized from prilocaine and cross-reacted to articaine, but not to other amide anesthetics. Cross-reactions between prilocaine and amide anesthetics were reviewed. As there seem to be no clear rules regarding cross-reactivity among various amide anesthetics, it is safest to test as many amide type anesthetics as possible in case of a delayed type allergy to any member of this family.

Contact Allergy and Cross-Reactions Caused by Prilocaine

Background: Allergic contact dermatitis from local amide anesthetics such as lidocaine (Xylocaine), bupivacaine (Marcaine, Bicain), mepivacaine (Carbocaine), etidocaine (Duranest), and prilocaine (Citanest) is rare. Allergic contact dermatitis from prilocaine has been reported only from EMLA cream. Objectives: We report on a patient sensitized from prilocaine used as a local infiltration anesthetic. Methods: Conventional patch testing with various local amide anesthetics as well as intracutaneous tests with amide anesthetics were performed. Results: Patch testing with EMLA cream (as is) (Astra, Sweden), containing prilocaine and lidocaine provoked an allergic patch test reaction, whereas patch testing with lidocaine was negative. Patch testing with Citanest containing 2% prilocaine and adrenaline was positive. Also articaine gave an allergic patch test reaction, whereas mepivacaine, benzocaine, and caine-mix were negative. Intracutaneous tests with prilocaine and articaine were positive. Conclusion: Our patient had been sensitized from prilocaine and cross-reacted to articaine, but not to other amide anesthetics. Cross-reactions between prilocaine and amide anesthetics were reviewed. As there seem to be no clear rules regarding cross-reactivity among various amide anesthetics, it is safest to test as many amide type anesthetics as possible in case of a delayed type allergy to any member of this family.

Contact allergy and cross-reactions caused by prilocaine

Background : Allergic contact dermatitis from local amide anesthetics such as lidocaine (Xylocaine), bupivacaine (Marcaine, Bicain), mepivacaine (Carbocaine), etidocaine (Duranest), and prilocaine (Citanest) is rare. Allergic contact dermatitis from prilocaine has been reported only from EMLA cream. Objectives : We report on a patient sensitized from prilocaine used as a local infiltration anesthetic. Methods : Conventional patch testing with various local amide anesthetics as well as intracutaneous tests with amide anesthetics were performed. Results : Patch testing with EMLA cream (as is) (Astra, Sweden), containing prilocaine and lidocaine provoked an allergic patch test reaction, whereas patch testing with lidocaine was negative. Patch testing with Citanest containing 2% prilocaine and adrenaline was positive. Also articaine gave an allergic patch test reaction, whereas mepivacaine, benzocaine, and caine-mix were negative. Intracutaneous tests with prilocaine and articaine were positive. Conclusion : Our patient had been sensitized from prilocaine and cross-reacted to articaine, but not to other amide anesthetics. Cross-reactions between prilocaine and amide anesthetics were reviewed. As there seem to be no clear rules regarding cross-reactivity among various amide anesthetics, it is safest to test as many amide type anesthetics as possible in case of a delayed type allergy to any member of this family.

Photochemical reactions of radical cations of dimethylformamide in freon matrices at 77 K

Spectral characteristics of the radical cations (RC) of DMF (λmax = 415 nm, emax = (2.6±0.8)·103 L mol−2 cm−2) stabilized in an irradiated glassy freon mixture (CFCl3 and CF2BrCF2Br) at 77 K were determined. Amide type radicals and RC of the matrix were shown to be formed by irradiation (λ=365–436 nm) of the radical cations of DMF in freon matrices using ESR and UV spectroscopy. The quantum yields of photoconversion of the DMF radical cations are independent of the wavelength of exciting light. It was found that the matrix structure affects the processes stabilizing the products of photoconversion of the DMF radical cations.

A New Synthetic Strategy towards Molecules with Mechanical Bonds: Nonionic Template Synthesis of Amide‐Linked Catenanes and Rotaxanes

AbstractAfter Sauvage et al. and Stoddart et al. had developed the now commonly used and well‐established catenane and rotaxane synthesis utilizing phenanthroline/Cu+ and bipyridinium/crown units, a new way to synthesize mechanical bonds was discovered in 1992—the synthesis of amide‐linked catenanes and rotaxanes around a neutral template. The formation of the template, which leads to the host–guest bond, does not proceed by covalent or ionic interaction, but by weak supramolecular interactions, such as hydrogen bonding, π‐stacking, π‐donor–π‐acceptor interaction, and steric complementarity. The simple synthetic units (arene dicarboxylic acid dichlorides and diamines) can be varied in an astonishing number of ways, few steps are required to obtain the target molecules, and the yields of these syntheses approach those of ordinary organic syntheses. After the preparation of [2]catenanes, it took only a few years to prepare [2]‐, [3]‐, and bis[2]‐rotaxanes of the amide type. The introduction of sulfonamide groups enabled alkylation of the sulfonamide nitrogen atom, and this made chemical reactions with catenanes and rotaxanes feasible. Intra‐ and intermolecular connections of catenanes and rotaxanes were then possible, and a molecule with the topology of a “pretzel” has recently been prepared. This allowed new insights into the molecular recognition processes of neutral guest and host substances, as well as further understanding of these processes in template synthesis, isomerism in catenanes, and the regioselectivity of the formation of catenane isomers. Competitive binding studies of guest molecules in the cavity of concave receptors with more than one binding site can be perfomed. These studies might result in higher synthetic yields of molecules with mechanical bonds and lead to further progress in the development of supramolecular nanostructures and molecular switches.