Spectrophotometric determination of cobalt in steel with 2-(2-thiazolylazo)-4-methyl-5-(sulfomethylamino) benzoic acid (TAMSMB)

Microchimica Acta - A method for the determination of cobalt in steel with 2-(2-thi-azolylazo)-4-methyl-5-(sulfomethylamino) benzoic acid (TAMSMB) is proposed. Iron and manganese were previously...     

New polymer syntheses. LXVI. Copolyester of 4-hydroxybenzoic acid and 3-(4'-hydroxyphenoxy)benzoic acid or 4-(3'-hydroxyphenoxy)benzoic acid

Copolyesters of 4-hydroxybenzoic acid (HBA) and 3-(4'-hydroxyphenoxy)benzoic acid were prepared by two different procedures. Either the acetyl derivatives were polycondensed in bulk at temperatures up to 300°C or they were polycondensed in an inert reactions medium (Marlotherm-S) at 340°C. Two analogous series of copolyesters were synthesized from 4-acetoxybenzoic acid (4-HBA) and 4-(3'-acetoxyphenoxy)benzoic acid. The copolyesters were characterized by elemental analyses, inherent viscosities, ¹H- and ¹³C-NMR spectroscopy, WAXS and DSC measurements, and by optical microscopy. All copolyesters synthesized in solution were highly crystalline materials which were neither meltable nor soluble. Part of the copolyesters prepared by polycondensation in bulk were semi-crystalline, meltable, and soluble. The copolyester derived from 3-(4'-hydroxyphenoxy)benzoic acid proved to be thermotropic forming a nematic melt, whereas the isomeric copolyesters of 4-(3'-hydroxyphenoxy)benzoic acid only formed isotropic melts. © 1993 John Wiley & Sons, Inc.     

Reaction of 2-(phenylamino)benzoic and 2-(phenylamino)- and 2-methyl-6-phenylpyridine-3-carboxylic acid hydrazides with succininc anhydride

Reactions of 2-(phenylamino)benzoic and 2-(phenylamino)- and 2-methyl-6-phenylpyridine-3-carboxylic acid hydrazides with succinic anhydride in organic solvents at room temperature gave the corresponding 4-(2-aroylhydrazinyl)-4-oxobutanoic acids. The reactions in boiling acetic acid afforded N-(2,5-dioxopyrrolidin-1-yl)benzamide or N-(2,5-dioxopyrrolidin-1-yl)pyridine-3-carboxamide.     

On the mechanism of the metalation of 2-(pyridin-3-yl)benzoic acid derivatives

The mechanism of the metalation of 2-(pyridin-3-yl)benzoic acid derivatives with strong bases is discussed.     

Synthesis and ring-chain isomerism of acid chlorides and amides of 2-(2-pyridyl and 2-quinolylcarbonyl) benzoic acids

The reaction of 2-(2 pyridytcarbonyl)benzoic acid with thionyl chloride affords an unexpected product of the intramolecular acylation of the pyridine nitrogen atom, namely, 6,11-dioxo-6,11-dihydrobenzo[blquinotizinium chloride. At the same time, 2-(2-quinotylcarbonyl)benzoic acid forms the expected cyclic acid chloride, namely, 3-(2-gitinotyl)-3-chlorophthalide in this reaction. Both compounds acylate ammonia and primary amines, including those with bulky alkyl groups (tert-butyl, 1-adamantyl, and 1,1,3,3-tetramethylbutyl) with the formation of 2-R-3-hydroxy-3-(2pyridyl- or 2-quinolyl)isoindolines. The protonation of the pyridine nitrogen atom of N-(1,1,3,3-tetramethylbutyl)-2-(2pyridylcarbonyl)benzamide, obtained in the open amide form, is accompanied by the closing of the isoindotinone ring; the deprotonation is accompanied by ring opening.Riga Technical University, Riga LV-1048. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 499–504, April, 1994. Original article submitted March 17, 1994.     

2-(4-Oxo-3,4-dihydro-2-quinazolinylmethyl)benzoic Acids

Condensation of 2-cyanomethylbenzoic acid with anthranilic acids gave a series of 2-(4-oxo-3,4-dihydro-2-quinazolinylmethyl)benzoic acids which are structural analogs of the alkaloid glycosminine (2-benzyl-1,2-dihydro-4-quinazolone).     

2-硝基-5-(N-甲基-N-十八烷基)氨基苯甲酸多层膜的制备和性质

用2-硝基-5-(N-甲基-N-十八烷基)氨基苯甲酸(NMOB)和花生酸制备了200层的交替多层膜, 测得其二次谐波信号强度与NMOB层数的平方成正比。论文着重讨论了NMOB的Y型膜和它与花生酸的交替膜中的取向, 并对两者之间的不同作了初步的解释。     

Conversion of 2-(4-carboxyphenyl)-6-nitrobenzothiazole to 4-(6-amino-5-hydroxybenzothiazol-2-yl)benzoic acid by a recombinant E. coli strain

E. coli C43(DE3)pNbzAHabA, expressing nitroreductase and mutase enzymes, converts 2-(4-carboxyphenyl)-6-nitrobenzothiazole to 4-(6-amino-5-hydroxybenzothiazol-2-yl)benzoic acid.     

Conformational polymorphism of 3-(azidomethyl)benzoic acid

Three conformational polymorphs of 3-(azidomethyl)benzoic acid, C₈H₇N₃O₂, are reported. All three structures maintain similar carboxylic acid dimers and π–π stacking. Crystal structure analysis and computational evaluations highlight the azidomethyl group as a source of conformational polymorphism, thus having potential implications in the design of solid-state reactions.     

Hydrogen-bonded liquid-crystalline complexes of polyester containing a pyridyl moiety with 4-(alkoxy)benzoic acid

Novel hydrogen-bonded polyester complexes from mesogenic 4-(butyloxy)benzoic acid (2a), 4-(octyloxy)benzoic acid (2b), 4-(dodecyloxy)benzoic acid (2c) and 4-(tetradecyloxy)benzoic acid (2d) as the hydrogen bond donors and a polyester (3) based on 2,6-pyridine dicarboxylic acid as the hydrogen bond acceptor were prepared by the melt method. The association by hydrogen bonding was confirmed by means of FTIR. The components were miscible up to 0.1 mole ratio of 2d and 2c versus the polyester repeat unit. The limiting mole ratio for 2b and 2a to 3 were 0.2 and 0.4, respectively. Phase separation in the supramolecular complexes occurred above these limiting values and a two phase system consisting of a polyester supramolecular complex and 4-(alkyloxy)benzoic acid was formed. This was due to weak hydrogen bonding between the low molecular acid (especially the acid with longer terminal alkoxy group) and pyridyl unit of polyester in comparison with thermodynamically more favorable dimerization of acid molecules. The liquid crystalline behavior of these supramolecular polymeric complexes was confirmed by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). It was found that 2a exhibits no mesomorphism when mixed with polyester. However, among the other acid derivatives, 2b exhibited stable mesogenic complexes.     

Evaluation of 2-(2-thiophenecarboxy)benzoic acid and related active metabolites in biological samples.

This paper describes a quantitative assay of 2-(2-thiophenecarboxy)benzoic acid and its systemic metabolites, namely salicylic acid and thiophenecarboxylic acid, by high-performance liquid chromatography with ultraviolet detection at 254 nm. Analytes were extracted from acidified samples with tert.-butylmethyl ether and separated with an RP-18 column (150 mm x 3 mm I.D., 5 microns particle size) with a mixture of 0.01 M potassium phosphate and methanol (70:30, v/v) at pH 3.1. The method proved to have the validation required for pharmacokinetic investigations in animals and humans.     

Preparation and X-ray structures of 3-[Bis(trifluoroacetoxy)iodo]benzoic acid and 3-[hydroxy(tosyloxy)iodo]benzoic acid: new recyclable hypervalent iodine reagents

Preparation, structural characterization, and reactivity of 3-[bis(trifluoroacetoxy)iodo]benzoic acid and 3-[hydroxy(tosyloxy)iodo]benzoic acid, new recyclable iodine(III) reagents derived from 3-iodosylbenzoic acid, are described. The reduced form of these reagents, 3-iodobenzoic acid, can be easily recovered from the reaction mixtures using ion-exchange resin or basic aqueous workup followed by acidification with HCl.     

Synthesis of Hybrid Compounds on the Basis of 4-[(1-Oxo-3,4-dihydro-2H-naphthalen-2-ylidene)methyl]benzoic acid

Russian Journal of Organic Chemistry - The reactions of 4-[(1-oxo-3,4-dihydro-2H-naphmalen-2-ylidene)methyl]benzoic acid with 3-(1,3-dioxobutane-1-yl)-2H-chromen-2-one in the presence of...     

One-pot synthesis of 2-（1-acyloxypentyl） benzoic acids

A one-pot synthesis of 2-（1-acyloxypcntyl） benzoic acids by trapping the carboxylatc/alkoxide dianion with acylating reagents following Grignard addition with n-BuMgBr to 2-formylbcnzoic acid was described. Compared with routine synthetic method, this novel procedure has the advantage of convenient operation and higher yields.     

Synthesis and transformations of 2- and 4-(2-Methylquinolin-4-ylamino)benzoic acids and ethyl 4-(2-methylquinolin-4-ylamino)benzoates and their fluorescent properties

2- and 4-(2-Methylquinolin-4-ylamino)benzoic acids and ethyl 4-(2-methylquinolin-4-ylamino)-benzoates having a substituent in the 6(8)-position of the quinoline ring were synthesized by reaction of the corresponding substituted 4-chloro-2-methylquinolines with 2- and 4-aminobenzoic acids and ethyl 4-aminobenzoate. Intramolecular cyclization of 2-(2-methylquinolin-4-ylamino)benzoic acids in concentrated sulfuric acid gave 7-hydroxy-6-methyldibenzo[b,h][1,6]naphthyridines, and ethyl 4-(2-methylquinolin-4-ylamino)benzoates were converted into 4-(2-methylquinolin-4-ylamino)benzoic acids by alkaline hydrolysis.     

Multienzymatic preparation of (−)-[3-(oxiran-2-yl)phenyl]methanol and (−)-3-(oxiran-2-yl)benzoic acid

The cascade use of enzymatic activities allows for the preparation of enantiomerically pure epoxides. In particular, using whole-cell biocatalysts we can prepare both (?)-[3-(oxiran-2-yl)phenyl]methanol and (?)-3-(oxiran-2-yl)benzoic acid in one-pot, two or three steps procedure. The yield is quantitative and enantiomeric purity greater than 95%. The selected biocatalysts contain a styrene monoxygenase from Pseudomonas fluorescens ST and a naphthalene dihydrodiol dehydrogenase from P. fluorescens N3, cloned and expressed in Escherichia coli.     

Synthesis and GCP II inhibitory activity of 4[4-(3-bromobenzyl)-5-hydroxyisoxazol-3-yl]benzoic acid heterocyclic analogs

A method for the synthesis of analogs of glutamate carboxypeptidase II inhibitor 4-[4-(3-bromobenzyl)-5-hydroxyisoxazol-3-yl]benzoic acid-4-[4-(3-bromobenzyl-5-hydroxypyrazol-3-yl]-benzoic acid and 4-[4-(3-bromobenzyl)-3-hydroxyisoxazol-5-yl]benzoic acid from 4-(2-ethoxycarbonylacetyl)benzoic acid was developed. The GCP II inhibitory activity of all the compounds synthesized was determined. Substitution of the 5-hydroxyisoxazole group by the 5-hydroxypyrazole group led toa complete loss of activity, while replacement with the 3-hydroxyylisoxazole gave the compound with slightly less inhibitoer activity comparing with the initial compound. __________ Translated from Khimiya Geteritsiklicheskikh Soedinenii, No. 11, 1693–1697, November, 2007.     

A mass spectral rearrangement of 2-(alkylamino)benzoic acid derivatives and related heterocyclic systems

The behavior of a series of 2-(alkylamino)benzoic acid derivatives and related heterocylic systems has been investigated using electron impact mass spectrometry and fragmentation pathways have been formulated. Deuterium-labeled and ¹³C-labeled compounds were used in this study. An interesting rearrangement of the alkylamino compounds, in which the alkyl substituent is incorporated into a fulvene ion, was observed. This rearrangement had previously been observed for 1-alkylisatins and l-alkyl-3-arylimino-2-indolinones.     

Synthesis of amino acid derivatives of 4-(1-adamantyl)benzoic acid obtained by transition metal ion catalyzed oxidation of 4-(1-adamantyl)toluene

An efficient synthesis of 4-(1-adamantyl)benzoic acid based on transition metal ion catalyzed oxidation of 4-(1-adamantyl)toluene has been developed. As a catalytic system, cobalt-manganese bromide with addition of manganese acetate was used. A series of amino acid derivatives of 4-(1-adamantyl)benzoic acid was then synthesized and characterized. These derivatives are novel intermediates potentially useful in the design of therapeutically active peptidomimetics with improved pharmacokinetic and pharmacodynamic parameters.     

Regioselectivities in deprotonation of 2-(4-chloro-2-pyridyl)benzoic acid and corresponding ester and amide

Upon treatment of ethyl 2-(4-chloro-2-pyridyl)benzoic acid, 2-(4-chloro-2-pyridyl)benzoate, and N,N-diisopropyl-2-(4-chloro-2-pyridyl)benzamide with LTMP at −75 °C in THF, the lithio derivatives at C5′ are generated regiospecifically, as demonstrated by subsequent quenching with electrophiles. The lithio derivative at C3′ is only evidenced from the benzamide at higher temperature (−50 °C), when treated with LTMP in THF; it instantly cyclizes to 1-chloro-4-azafluorenone. The latter is converted to onychine, an alkaloid endowed with anticandidal activity.