Aryl Esters Of Acids Research Articles

Phosphonamidates of Camphorsultam: Versatile Building Blocks for the Synthesis of P‐Chiral Phosphorous(V) Compounds

AbstractCamphorsultam was utilized for the optical resolution of P‐chiral phosphorous compounds. After chromatographic separation of diastereomeric RP‐ and SP‐phosphonamidate intermediates, subsequent substitution reactions with phenol derivatives yielded P‐chiral phosphonic acid aryl esters with excellent enantioselectivities. In these processes, chiral sulfonamide of camphorsultam demonstrated superior abilities as an optical‐resolving agent and a good leaving group. This method was applied to the synthesis of P‐chiral phosphinic esters, phosphonamidates, and thiophosphonate diesters.

Synthesis and biological activities of 1H-indole-1-carboxylic acid aryl esters as a marine antifouling coating

A series of indole-1-carboxylic acid aryl esters was synthesized with indole and substituted phenols as raw materials. The structures of the target compounds were validated by IR and 1H-NMR spectroscopies. The inhibitory activities of the target compounds and their potencies against marine fouling organisms were investigated. The results showed that the target compounds had significant inhibitory effects on the growth of three seaweeds: Isochrysis galbana, Platymonas subcordiformis, and Navicula, and the target compounds also had excellent inhibition on the survival of barnacle larvae. The substituent structure–activity relationships revealed a significant effect on biological inhibition activity: Compounds substituted by electron-withdrawing groups had greater bioactivities than those containing electron-donating groups. Release rate of antifoulant and marine field tests indicated the final compounds had an outstanding antifouling potency against marine fouling organisms.

Synthesis and Biological Activity of Quinoline-2-Carboxylic Acid Aryl Esters and Amides

Derivatives of quinoline-4-carboxylic acid are known to possess anti-inflammatory and analgesic activity. However, structurally analogous amides and esters of quinoline-2-carboxylic acid are insufficiently studied. In the present work, esters and substituted amides of quinoline-2-carboxylic acid were prepared by reacting quinoline-2-carboxylic acid chloride with phenol or arylamine, respectively. The structures of the synthesized compounds were confirmed using spectroscopic data; the purities, TLC. The physicochemical properties of the target reaction products were determined. Animal experiments determined the anti-inflammatory and analgesic activities as compared with the standard drug diclofenac sodium. The developed method for synthesizing quinoline-2-carboxylic acid derivatives could be used in preparative organic chemistry to prepare potentially biologically active quinoline derivatives.

Palladium-catalysed enantioselective hydroaryloxycarbonylation of styrenes by 4-substituted phenols

Palladium-catalysed hydroaryloxycarbonylation of a set of styrenes was performed under carbon monoxide atmosphere towards the corresponding propanoic acid aryl esters. The reaction conditions were optimized and several phosphine ligands (achiral mono- and bidentate, chiral (enantiopure) bidentate) were investigated in Pd-catalyst systems generated in situ. In general, the application of mono- and diphosphines favours the formation of branched and linear regioisomers, respectively. Carrying out the reaction in enantioselective fashion, the DIOP modified catalyst proved to be the most efficient one among the chiral ligands studied. The substituent effect on the regio- and enantioselectivity was also investigated regarding both the substrate (styrene) and the O-nucleophile (phenol) with Pd-DIOP system. Simultaneous modifications of substituents of the ‘reactants’ were also carried out. The preference of the linear ester regioisomer and low enantiomeric excesses were obtained.

Physical Nature of Fatty Acid Amide Hydrolase Interactions with Its Inhibitors: Testing a Simple Nonempirical Scoring Model.

Fatty acid amide hydrolase (FAAH) is an enzyme responsible for the deactivating hydrolysis of fatty acid ethanolamide neuromodulators. FAAH inhibitors have gained considerable interest due to their possible application in the treatment of anxiety, inflammation, and pain. In the context of inhibitor design, the availability of reliable computational tools for predicting binding affinity is still a challenging task, and it is now well understood that empirical scoring functions have several limitations that in principle could be overcome by quantum mechanics. Herein, systematic ab initio analyses of FAAH interactions with a series of inhibitors belonging to the class of the N-alkylcarbamic acid aryl esters have been performed. In contrast to our earlier studies of other classes of enzyme-inhibitor complexes, reasonable correlation with experimental results required us to consider correlation effects along with electrostatic term. Therefore, the simplest comprehensive nonempirical model allowing for qualitative predictions of binding affinities for FAAH ligands consists of electrostatic multipole and second-order dispersion terms. Such a model has been validated against the relative stabilities of the benchmark S66 set of biomolecular complexes. As it does not involve parameters fitted to experimentally derived data, this model offers a unique opportunity for generally applicable inhibitor design and virtual screening.

Cinchona based squaramide catalysed enantioselective Michael addition of α-nitrophosphonates to aryl acrylates: enantioselective synthesis of quaternary α-aminophosphonates

Several cinchona based squaramide catalysts were applied to the asymmetric Michael addition of α-nitroethylphosphonates to acrylic acid aryl esters, resulting in high yields and enantioselectivities. The absolute configuration of one of the quaternary α-nitrophosphonate adducts was deduced from its experimental and calculated CD spectra. The adducts were reduced to their cyclic aminophosphonates by catalytic hydrogenation.

Structure-property relationships of a class of carbamate-based fatty acid amide hydrolase (FAAH) inhibitors: chemical and biological stability.

Cyclohexylcarbamic acid aryl esters are a class of fatty acid amide hydrolase (FAAH) inhibitors, which includes the reference compound URB597. The reactivity of their carbamate fragment is involved in pharmacological activity and may affect their pharmacokinetic and toxicological properties. We conducted in vitro stability experiments in chemical and biological environments to investigate the structure-stability relationships in this class of compounds. The results show that electrophilicity of the carbamate influences chemical stability, as suggested by the relation between the rate constant of alkaline hydrolysis (log k(pH9)) and the energy of the lowest unoccupied molecular orbital (LUMO). Introduction of small electron-donor substituents at conjugated positions of the O-aryl moiety increased the overall hydrolytic stability of the carbamate group without affecting FAAH inhibitory potency, whereas peripheral non-conjugated hydrophilic groups, which favor FAAH recognition, helped decrease oxidative metabolism in the liver.

Further Advances in the Synthesis of Endocannabinoid‐Related Ligands

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Further advances in the synthesis of endocannabinoid-related ligands

Recent advances in the synthesis of endocannabinoid-related ligands for the period 2001-2004 are covered in this review. During this period the first solid phase synthesis of anandamide (AEA) analogs was developed, which allows modification at both the head group and the end pentyl chain. Synthesis of water-soluble prodrugs of noladin ether was reported, which are chemically stable, rapidly release noladin ether under enzymatic conditions and are shown to reduce intraocular pressure. The structure-activity relationships (SAR) of alkylcarbamic acid aryl esters and the discovery of potent archidonylsulfonyl derivatives as fatty acid amide hydrolase (FAAH) inhibitors are summarized. Recent synthetic developments in the controversial area of anandamide membrane transporter (AMT) inhibitors are also discussed.

Design, synthesis, and structure-activity relationships of alkylcarbamic acid aryl esters, a new class of fatty acid amide hydrolase inhibitors.

Fatty acid amide hydrolase (FAAH), an intracellular serine hydrolase enzyme, participates in the deactivation of fatty acid ethanolamides such as the endogenous cannabinoid anandamide, the intestinal satiety factor oleoylethanolamide, and the peripheral analgesic and anti-inflammatory factor palmitoylethanolamide. In the present study, we report on the design, synthesis, and structure-activity relationships (SAR) of a novel class of potent, selective, and systemically active inhibitors of FAAH activity, which we have recently shown to exert potent anxiolytic-like effects in rats. These compounds are characterized by a carbamic template substituted with alkyl or aryl groups at their O- and N-termini. Most compounds inhibit FAAH, but not several other serine hydrolases, with potencies that depend on the size and shape of the substituents. Initial SAR investigations suggested that the requirements for optimal potency are a lipophilic N-alkyl substituent (such as n-butyl or cyclohexyl) and a bent O-aryl substituent. Furthermore, the carbamic group is essential for activity. A 3D-QSAR analysis on the alkylcarbamic acid aryl esters showed that the size and shape of the O-aryl moiety are correlated with FAAH inhibitory potency. A CoMSIA model was constructed, indicating that whereas the steric occupation of an area corresponding to the meta position of an O-phenyl ring improves potency, a region of low steric tolerance on the enzyme active site exists corresponding to the para position of the same ring. The bent shape of the O-aryl moieties that best fit the enzyme surface closely resembles the folded conformations observed in the complexes of unsaturated fatty acids with different proteins. URB524 (N-cyclohexylcarbamic acid biphenyl-3-yl ester, 9g) is the most potent compound of the series (IC(50) = 63 nM) and was therefore selected for further optimization.

Molecular markers of anthropogenic activity in sediments of the Havel and Spree Rivers (Germany)

Detailed gas chromatographic/mass spectrometric analyses have been applied to sediment samples of the Havel and Spree River, tributaries to the Elbe River, in order to identify specific molecular markers of anthropogenic activities. Despite a wide variety of lipophilic organic compounds from diffuse anthropogenic contamination, a local emission of an industrial point source was reflected by specific markers including halogenated compounds and nitrogen containing substances (4-ethylnitrobenzene, formyl piperidine, acetyl piperidine). In addition to well-known anthropogenic markers various new molecular tracers were detected and are discussed, namely plasticizers (alkylsulfonic acid aryl esters, tributyl and tricresyl phosphates), synthetic fragrances (galaxolide, tonalide, 4-oxoisophorone), additives of personal care products (4-methoxycinnamic acid 2-ethylhexyl ester, benzyl benzoate, dibenzyl ether, benzophenone), occurring due to sewage treatment plant input.

Catalysis of the hydrolysis of esters of phosphorus acids byn-decylammonium chloride /n-decylamine mixed micelles

The effect ofn-decylammonium chloride/n-decylamine mixed micelles on the rate of hydrolysis of aryl esters of acids of four-coordinate phosphorus was studied spectrophotometrically. The shape of the concentration curves is characteristic of the micellar catalysis reactions. The binding constants of the substrate, critical micelle concentrations, and the rate constants in the micellar phase were determined. A specific effect of the structure of substrates on these parameters was shown.

Palladium-catalyzed aryloxycarbonylation of terminal alkynes

Carbonylation of terminal alkynes using palladium-phosphine complexes proceeds efficiently in the presence of 3- or 4-substituted phenols to give the corresponding 2-substituted 2-propenoic acid aryl esters in good selectivity and yield.

Synthesis, mesomorphic properties and potential applications of aryl esters of 4-n-alkylcyclohexene-1-carboxylic acids in electrooptic displays

Abstract The reaction of 4-substituted phenols with 4-n-alkylcyclohexene-1-carbonyl chlorides, which differ in the position of their double bond in the ring, has yielded the corresponding esters. Investigation of their mesophoric properties including the electrooptic parameters of mixtures containing these compounds show that aryl esters of acids containing the double bond in the second position of the cyclohexene fragment are the most promising for use as components of liquid crystal mixtures.

ChemInform Abstract: Isomerization of Aryl Esters of Acids of Pentavalent Phosphorus.

AbstractThe aryl phosphinates or phosphonates (I) with at least one free o‐position in the aroxy group rearrange in the presence of a strong base to give the corresponding 2‐hydroxyaryl compounds (II).

Medicinal chemical studies on synthetic protease inhibitors, trans-4-guanidinomethylcyclohexanecarboxylic acid aryl esters.

trans-4-Guanidinomethylcyclohexanecarboxylic acid (trans-GMCHA) aryl esters were synthesized and tested for inhibitory effects on serine proteases, trypsin, chymotrypsin, plasmin, plasma kallikrein, pancreatic kallikrein, urokinase and thrombin. In general, these compounds showed strong inhibitory effects on chymotrypsin, pancreatic kallikrein and urokinase, but the effects varied greatly depending on the substituent in the benzene nucleus. Some of the trans-GMCHA aryl esters strongly inhibited compound 48/80-induced histamine release from mast cells / the p-tert-butylphenyl ester was especially active.

ChemInform Abstract: N-SUBSTITUTED N-(ISOCYANATOCARBONYL)CARBAMIC ACID ARYL ESTERS AND THEIR DIMERS

Chemischer InformationsdienstVolume 14, Issue 13 Isocyclic Compounds ChemInform Abstract: N-SUBSTITUTED N-(ISOCYANATOCARBONYL)CARBAMIC ACID ARYL ESTERS AND THEIR DIMERS E. + KUEHLE, E. + KUEHLESearch for more papers by this authorH. HAGEMANN, H. HAGEMANNSearch for more papers by this authorL. OEHLMANN, L. OEHLMANNSearch for more papers by this authorD. WENDISCH, D. WENDISCHSearch for more papers by this author E. + KUEHLE, E. + KUEHLESearch for more papers by this authorH. HAGEMANN, H. HAGEMANNSearch for more papers by this authorL. OEHLMANN, L. OEHLMANNSearch for more papers by this authorD. WENDISCH, D. WENDISCHSearch for more papers by this author First published: March 29, 1983 https://doi.org/10.1002/chin.198313194AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume14, Issue13March 29, 1983 RelatedInformation

Organophosphorus chemistry—V : Thermal transformation of the cyclohexylammonium salt of O-aryl N-cyclohexyl phosphoramidic acids into sym-pyrophosphates

The formation of pyrophosphates from phosphorus monoamidates was studied by TGA associated with chromatographic techniques upto 320°. Above this temperature the salts decomposed completely. Other compounds were also formed: diamidophosphoric acid aryl esters, pyrophosphorus amidic acids, cyclohexylamine, phenols and a number of minor thermoproducts. The influence of substituents attached to the aromatic ring on the over-all rate of decomposition reaction showed the order: t-Bu > Me > H > Cl. Anomalous results were found for NO 2. Second order rate constants were measured. A mechanism in two steps is suggested for the reaction investigated. Initial formation of free phosphoramidic acid as proposed by Clark appears to be unnecessary. Pyrolysis stequiometric equation was proposed.

Water Soluble Steroids with Catalytic Substituents II. Synthesis of 3β-(4(5)-Imidazolyl)-5α-androstane-11β, 17β,-diamine and Comparison of its Catalytic Properties with Those of 17β-(4(5)-Imidazolyl)-5α-androstane-3β, 11β-diamine

3β-(4(5)-Imidazolyl)-5α-androstane-11β,17β-diamine, 15, has been synthesized in a multistep process from adrenosterone, 2, starting with lithium ammonia reduction to give 11α,17β-dihydroxy-5α-androstan-3-one, 3, which was converted to its diacetate, 4. Ethynylation at the 3 keto group gave the ethynyl triol 5, purified as its11,17-diacetate 6. Acid catalyzed rearrangement of 6 gave 3-acetyl-5α-androst-2-ene-11α,17β-diol diacetate, 7. This was hydrogenated, and then subjected to base catalyzed hydrolysis and equilibration to give crystalline 3β-acetyl-5α-androstane-11α,17β-diol, 9, which was converted to 3β-acetoxyacetyl-5α-androstane-11α,17β-diol, 10, using lead tetraacetate. After hydrolysis to the triol, 11, the Weidenhagen reaction led to formation of 3β-imidazolyl-5α-androstane-11α,17β-diol, 12. Finally oxidation to the dione, 13, formation of the dioxime, 14, and hydrogénation give 15. As expected 15 is a better catalyst than 17β-(4(5)-imidazolyl-5α-androstane-3β,11β-diamine, 1, for the hydrolysis of aryl esters of acids with hydrophobic substituents, but the effect is small. With 1 there is a marked electrostatic rate enhancement or retardation when charged groups are present on the aryl esters; this effect is much smaller for 15.

Neue Methoden zur Herstellung von Carbonsäure‐arylestern. Über aktivierte Ester VIII

AbstractTwo new methods for preparing carboxylic acid aryl esters are presented. They consist in reacting the carboxylic acid with (a) aryl sulfites or (b) aryl phosphites in the presence of pyridine. A possible mechanism of the sulfite method is discussed.