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.     

2-(2-Hydroxy-4-methoxybenzoyl)benzoic acid derivatives of Group 4 metal alkoxides

Continued exploration of the coordination behavior of derivatives of 2-benzophenone-based ligands with metal alkoxides ([M(OR)₄]) was undertaken from the reaction of 2-(2-hydroxy-4-methoxybenzoyl)benzoic acid (H₂-OBzA) with a series of Group 4 precursors. The products of these reactions were identified as: [(OR)₂Ti(μ-(c,c-OBzA))]₂ (OR?=?OCHMe₂ (OPrⁱ; 1 ?2tol); OCMe₃ (OBu^t; 2 ?THF); OCH₂CMe₃ (ONep; 3)), [[(OPrⁱ)₃Ti(μ-OPrⁱ)Ti(OPrⁱ)₂]₂(μ-(μ_c,μ-OBzA))₂]₂ (4), [(ONep)₃Zr(μ-ONep)₂Zr(ONep)₂]₂(μ-(c,μ-OBzA)₂) (5 ?tol), [(py)(OBu^t)₃Zr]₂(μ-(c,c-OBzA)) (6), [(OBu^t)₂Hf(μ-OBu^t)]₂(μ-(c,η¹-OBzA)) (7) where ‘c’?=?chelating or η²; ‘μ’?=?bridging or η¹,η¹(O,O’); and μ_c?=?bridging chelating or η¹,η¹(O,O’); η^2?:?η¹. The metal centers for each of these compounds adopt a pseudo-octahedral geometry employing the OBzA ligand in numerous binding modes. The different functional oxygens (carboxylate, hydroxyl, and carbonyl) were employed in a variety of coordination modes for 1–7. The complexity of these OBzA-modified compounds is driven by a combination of the coordination behavior of the OBzA moieties, the size of the metal cation, and the pendant chain of the OR ligand. Solution NMR indicates a complex structure exists in solution that was considered to be consistent with the solid-state structure.     

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.     

Crystal structure of benzoic acid 4-nitrobenzylidenhydrazide

The crystal structure of benzoic acid 4-nitrobenzylidenhydrazide has been determined. Crystal data: crystal system — monoclinic, a = 7.101(9) Å, b = 25.48(3) Å, c = 7.730(11) Å; β = 112.43(9)°, space group P2₁/n, Z = 4, R = 0.038. The compound under investigation has a non-planar structure in general, and the substituents at azomethine N-C bond are in E-position. Root-mean-square planes of the six-memebered heterocycles make angles of 29.9° and 37.7° to fairly planar hydrazine fragment. In crystalline state the compound forms layers, the molecules within the layers being linked by C-H...O bonds. Neighboring layers are connected by hydrogen bonds between carbonyl oxygen atoms and amide hydrogens.     

Crystal and molecular structures of 2-(4-chlorophenyl)-5,7-dimethoxyquinolin-4-yl phenyl bis(2-chloroethyl) phosphoramidate

2-(4-Chlorophenyl)-5,7-dimethoxyquinolin-4-yl phenyl bis(2-chloroethyl)phosphoramidate is synthesized and characterized by NMR, IR and single crystal X-ray crystallography. The crystal is triclinic, P[`1]P\bar 1 space group, with a = 9.5188(19) ?, b = 12.856(3) ?, c = 13.250(3) ?, V = 1412.0(5) ?)³, and Z = 2 (at 291(2) K). The crystal packing arrangement indicates that the molecule is stacked through π...π aromatic stacking interactions.     

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...     

Hydrothermal syntheses and structures of transition metal 2-(4,5-diphenyl-1H-imidazol-2-yl)benzoic acid complexes

Two new transition metal complexes, [Zn(Hdiba)₂(H₂O)]?·?H₂O (1) and [Cu(Hdiba)₂] (2) (H₂diba?=?2-(4,5-diphenyl-1H-imidazol-2-yl)benzoic acid), were synthesized and characterized by IR, elemental analysis, and single-crystal X-ray diffraction. Complex 1 exhibits a monomeric structure, while 2 displays a dimeric structure. Both structures extend to 2-D supramolecular networks via hydrogen bonds. Thermal stabilities of 1 and 2 and photophysical properties of 1 are also discussed.     

Synthesis and characterization of poly[4-(4-hydroxyphenoxy) benzoic acid]

Poly[4-(4-hydroxyphenoxy) benzoic acid] was prepared by the bulk polycondensation of 4-(4-acetoxyphenoxy) benzoic acid. Polycondensation was conducted at 350°C for 3 h under a reduced pressure of 0.1 mmHg and gave a polymer with X?n of 255. The polymer was characterized by elemental analysis, IR spectroscopy, differential scanning calorimetry, and wide-angle X-ray measurement. The crystal/nematic and nematic/isotropic phase transition temperatures of polymer, which depend on the molecular weight, were observed at about 300°C and 410°C, respectively. The polymers with low molecular weights showed nematic textures above 300°C. This nematic/isotropic phase transition temperature is lower than that of poly (4-hydroxybenzoic acid). This thermal behavior of polymer comes from ether units, which increase the flexibility (the rotation or torsion of skeletal bonds) of the polymer chain. © 1994 John Wiley & Sons, Inc.     

Synthesis,characterization and crystal structures of 2-[(E)-2-(4-hydroxy-3,5-dimethylphenyl)-1-diazenyl]benzoic acid and its polymeric and monomeric triorganotin(IV) complexes

Three triorganotin(IV) complexes of composition R₃SnLH (R = Me, Bu and Ph and LH = 2-[(E)-2-(4-hydroxy-3,5-dimethylphenyl)-1-diazenyl]benzoate) have been synthesized and characterized by ¹H, ¹³C, ¹¹⁹Sn NMR, and IR spectroscopic techniques in combination with elemental analysis. The crystal structures of the carboxylate ligand HO₂CC₆H₄{NN(C₆H₂-4-OH-3,5-(CH₃)₂)}-o in its neutral form and three triorganotin(IV) complexes, viz., polymeric (R₃Sn[O₂CC₆H₄{N–N(H)(C₆H₂-4-O-3,5-(CH₃)₂)}-o])_n (R = Me (1) and Bu (2)) and monomeric Ph₃Sn[O₂CC₆H₄{N–N(H)(C₆H₂-4-O-3,5-(CH₃)₂)}-o] (3) complexes are reported. The polymeric complexes 1 and 2 exist as extended chains in which the LH-bridged Sn-atoms adopt a trans-R₃SnO₂ trigonal bipyramidal configuration with R groups in the equatorial positions and the axial sites occupied by an oxygen atom from the carboxylate ligand and the phenoxide O atom of the next carboxylate ligand. The Sn atom in complex 3 has a distorted tetrahedral geometry. In all three complexes, the carboxylate ligand is in the zwitterionic form with the phenolic proton moved to the nearby azo nitrogen atom, in contrast to the free carboxylic acid ligand which is in the azo form.     

Synthesis,characterization and crystal structures of 2-[(E)-2-(4-hydroxy-3,5-dimethylphenyl)-1-diazenyl]benzoic acid and its polymeric and monomeric triorganotin(IV) complexes

Three triorganotin(IV) complexes of composition R₃SnLH (R = Me, Bu and Ph and LH = 2-[(E)-2-(4-hydroxy-3,5-dimethylphenyl)-1-diazenyl]benzoate) have been synthesized and characterized by ¹H, ¹³C, ¹¹⁹Sn NMR, and IR spectroscopic techniques in combination with elemental analysis. The crystal structures of the carboxylate ligand HO₂CC₆H₄{NN(C₆H₂-4-OH-3,5-(CH₃)₂)}-o in its neutral form and three triorganotin(IV) complexes, viz., polymeric (R₃Sn[O₂CC₆H₄{N–N(H)(C₆H₂-4-O-3,5-(CH₃)₂)}-o])_n (R = Me (1) and Bu (2)) and monomeric Ph₃Sn[O₂CC₆H₄{N–N(H)(C₆H₂-4-O-3,5-(CH₃)₂)}-o] (3) complexes are reported. The polymeric complexes 1 and 2 exist as extended chains in which the LH-bridged Sn-atoms adopt a trans-R₃SnO₂ trigonal bipyramidal configuration with R groups in the equatorial positions and the axial sites occupied by an oxygen atom from the carboxylate ligand and the phenoxide O atom of the next carboxylate ligand. The Sn atom in complex 3 has a distorted tetrahedral geometry. In all three complexes, the carboxylate ligand is in the zwitterionic form with the phenolic proton moved to the nearby azo nitrogen atom, in contrast to the free carboxylic acid ligand which is in the azo form.     

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.     

Antimicrobial activity of some new thioureides derived from 2-(4-chlorophenoxymethyl)benzoic acid

We report here the characterisation of eight newly synthesized thioureides of 2-(4-chlorophenoxymethyl)-benzoic acid and the evaluation of the in vitro antimicrobial activity of the new compounds against Gram-positive [Listeria monocytogenes,Staphylococcus aureus, Bacillus subtilis], Gram-negative [Psedomonas aeruginosa,Escherichia coli, Salmonella enteritidis], as well as Candida spp., using both reference and clinical multidrug resistant strains to establish the minimal inhibitory concentration (MIC)values. Our results showed that the tested compounds exhibited specific antimicrobial activities, both concerning the spectrum of antimicrobial activity and the corresponding MIC values, which ranged widely between 1024 and 32 mug/mL, depending on the nature and position of the substituents on the benzene ring. The most active compounds were N-[2-(4-chlorophenoxymethyl)-benzoyl]-N'-(2,6-dichlorophenyl)-thiourea (5 g) and N-[2-(4-chlorophenoxymethyl)-benzoyl]-N'-(4-bromophenyl)-thiourea (5h), which showed a broad spectrum of antimicrobial activity against enterobacterial strains (E. coli and S. enteritidis),P. aeruginosa, S. aureus and Candida spp. All the tested compounds except 5f were highly active against S. aureus (MIC=32 mug/mL), suggesting their possible use in the treatment of MRSA infections. Four of compounds also exhibited antifungal activity (MIC =256-32 microg/mL) against C. albicans, but L. monocytogenes as well as B. subtilis were resistant to all tested compounds. Our studies thus demonstrated that among other biological activities,the thioureides of 2-(4-chlorophenoxymethyl)-benzoic acid also exhibit selective and effective antimicrobial properties that could lead to the selection and use of these compounds as efficient antimicrobial agents, especially for the treatment of multidrug resistant infections.     

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).     

Syntheses and characterizations of five coordination polymers constructed by 3,5-bis(pyridin-3-ylmethoxy)benzoic acid ligand

Five coordination polymers, namely [Cd(L3)₂]·H₂O (1), [Zn(L3)₂] (2), [Co(L3)₂] (3), [Ni(L3)₂] (4) and [Cu₂(L3)₂]·3H₂O (5), where L3 = 3,5-bis(pyridin-3-ylmethoxy)benzoic acid, have been synthesized under hydrothermal conditions. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and thermogravimetric (TG) analyses. Compound 1 is a binodal (3,4)-connected net with (6³)(6⁶) topology. Compounds 2–4 are isostructural and described by the uninodal (4,4)-connected net with (4⁴ · 6²) Schläfli symbol. The structure of 5 is a 2D binodal (6,3) net. In addition, the luminescent properties of compounds 1 and 2 have been studied in the solid state at room temperature.     

Crystal structures of monohalogenated benzoic acids

Crystal structures resulting from a combination of different types of specific intermolecular interactions have been analysed using examples of 12 monohalogenated benzoic acids (HBA). These have been compared with structures known for corresponding monofunctional compounds, namely benzoic acid, fluorobenzene, chlorobenzene and iodobenzene. It is found that common for carboxylic acids centrosymmetric hydrogen-bonded dimers exist in all HBA, and at the same time a degree of halogen atoms aggregation is rather high in the most part of HBA, similarly to chlorobenzene and iodobenzene crystals. Previously reported tendency to increasing degree of Hal-aggregation in the sequence F < Cl ≤ Br ≤ I is confirmed. It is remarkable that a stacking motif of benzene rings is realised in all HBA crystals though it is absent in all considered monofunctional substances.     

Reactions of aromatic dithiols with allyl glycidyl ether and 4-(oxiran-2-ylmethyl)morpholine

A reaction of allyl glycidyl ether and 4-(oxiran-2-ylmethyl)morpholine with aromatic dithiols furnished new substituted sulfur-containing propan-2-ols. The oxirane ring opening upon the action of aromatic dithiols follows a classic version and obeys the Krasuskii rule. O-Acetyl derivatives of some propan-2-ols synthesized were obtained as well.