Solubility of Oxygen in Some 1-1, 2-1, 1-2, and 2-2 Electrolytes as a Function of Concentration at 25°C

The solubility of oxygen has been measured in a number of electrolytes [(LiCl, KCl, RbCl, CsCl, NaF, NaBr, NaI, NaNO₃, KBr, KI, KNO₃, CaCl₂, SrCl₂, BaCl₂, Li₂SO₄, K₂SO₄, Mn(NO₃)₃)] as a function of concentration at 25°C. The solubilities, mol (kg-H₂O)^–1, have been fitted to a function of the molality m (standard deviation < 3mol-kg^–1)

Design,Synthesis and Biological Activity of Ethyl 2-（N-Substituted-arylsulfonamido）-2-oxoacetate

Thirteen new ethyl 2-（N-substituted-arylsulfonamido）-2-oxoacetates（3a-3m）, based on the structure of Ketol-acid reductoisomerase（KARI） inhibitor IpOHA, were designed and synthesized. Their structures were established on the basis of ^1H NMR, IR, MS, and elemental analyses. The bioassay result reveals that the structural changes from hydroxyl group on the N atom of IpOHA to arylsulfonyl groups does not enhance the inhibitory activity of the compounds to KARI in vitro. Compounds 3c, 3h, 3k, and 3m are more effective than IpOHA against the monocotyledonous bamygrass at 100 ug/mL in herbicidal tests.     

Synthesis of the 3-0, 4-0 and 6-0 Sulfates of Methyl 2-amino-2-deoxy-α-D-Glucopyranoside

Abstract

Starting with methyl 2-(benzyloxycarbonyl)amino-2-deoxy-α-D-glucopyranoside (1), the isomeric methyl 2-amino-2-deoxy-α-D-glucopyranoside 3-, 4-, and 6-sulfates have each been prepared by sulfation of suitably blocked intermediates. Tritylation and acetylation of 1 followed by detritylation gave methyl 3,4-di-0-acetyl-2-(benzyloxycarbonyl)amino-2-deoxy-α-D-glucopyranoside (3), having a free 6-hydroxyl group. Base catalyzed 0–4→0–6 acetyl migration provided the corresponding 3,6 di-O-acetyl derivative (4) posessing a free 4-hydroxyl group. Preparation of methyl 4,6-0-benzylidene-2-(benzyloxycarbonyl)amino-2-deoxy-α-D-glucopyranoside (9) provided the intermediate bearing a free 3-hydroxyl group. 0-sulfation of 3, 4, and 9 was effected with the pyridine sulfur trioxide complex in dry pyridine.     

Baker's yeast-induced asymmetric reduction of α-ketosulfides: synthesis of optically active 1-(benzothiazol-2-ylsulfanyl)-2-alkanols, 2-alkanols,and thiiranes

1-(Benzothiazol-2-ylsulfanyl)-2-alkanols 3 were prepared in very high enantiomeric excess by baker's yeast-induced asymmetric reduction of 1-(benzothiazol-2-ylsulfanyl)-2-alkanones 1. Conversion of 3 into optically active simple 2-alkanols 4 and thiiranes 2 by reductive desulfurization and base treatment, respectively, is also described. The absolute configuration of the new compounds synthesized has been established by chemical correlation and specific rotation comparison.     

Reaction of 2-(4,5-dihydrofur-3-yl)-1,3-diphenyl-1,3-diaza-2-2λ3-phospholidine withC,N-diphenylnitriliminewithC,N-diphenylnitrilimine

The reaction of 2-(4,5-dihydrofur-3-yl)-1,3-diphenyl-1,3-diaza-2λ³-phospholidine withC,N-diphenylnitrilimine is a multistage process, in the course of which the 1,2,4-diazaphosphorine ring is formed and both rings of the initial organophosphorus compound are cleaved. 5-(2-Chloroethyl)-4-(N,N′-diphenylethylenediamino)-1,3-diphenyl-1,4-dihydro-1, 2,4λ⁵-diazaphosphorine was obtained as the final product. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 125–128, January, 2000.     

Synthesis of α-[2-(2, 4-Dichlorophenoxy) Propionyloxy] Alkyl Phosphonates

Somenewphosphonatederivativeshaveshownexcellentbiologicalactivityandthusdrewourincreasingattention.DUringpastfewyears,wehavesynthesizedandstudiedseveralseriesofthiskindofcompoundswhichhaveherbicidalactivity.['1Amongthem,astriesofsubstitutedphenoxyacetoxyalkylphosphonatesisatypicalone,andsomecompoundsexhibitbetterherbicidalactivities.Inordertoexaminefurtherintotheher-bicidalactivitiesofnewphosphonatederivatives,wedesignedanothernewcompoundsQ-L2-(2,4-dichlorophenoxypropionyloxy)Jalkylphosphona…     

Synthesis of 5-[5-(α-Naphthyl)-2H-Tetrazol-2-Methylene]-2-Aroylamino-1, 3,4-Thiadiazoles

Introduction Acylthiosemicarbazides have been reported to possess extensive physiological activities. Substituted thiadiazoles are known to exhibit fungicidal and insecticidal activities. Chen Limin and her coworkers reported that the cyclization of 1[5-(3'-pyridyl )-2H-tetrazol-2-acetyl-]-4-acylthiosemicarbazides gave 5-[5-(3'-     

Studies on Mechanism of Chemiluminescence Reaction of 2, 6, 7-Trihydroxyl-9-(4'-chlorophenyl )-3-fluorone

1INTRoDUCTIONPhenylfluoroneisanimportanttypeofreagentinanalytica1chemistry"~'>.Themoleculesofthisreagenthavearigidplanarstructuret5'6i,sotheenergyofmolecularorbitsofthereagentscanbecalculatedbyHuckelmolecularorbitalmethod(HMO).WehadtriedtoassigndissociationconstantsforsomesuchreagentsbyacombinedspectrophotometricandHMOmethodt7'8i.Them.thodissimpleandtheresultsaresatisfactory.Inthispaper,apossiblemechanismforcatalyticchemiluminescencere-actionofCl-PFisproposedonthebasisofstudyingchemil…     

A Convenient Synthesis of 2, 3 - DI- O - Acetyl-1, 6 - Anhydro- β - D – Glucopyranose

Abstract

1, 2, 3-Tri-O-acetyl-6-O-benzyl-4-O-chloroacetyl-α- and -β-D-glucopyranose (4α β)were derived from 1, 2, 3-tri-O-acetyl-4, 6- O -benzyl-idehe-β-D-giucopyranose (1) in two steps. Compound 1, 1, 2, 3-tri-O -acetyl-β-D-glucopyranose (2), and 4α,β were subjected to the cyclization reaction using Lewis acids ( SnCl₄ and BF₃-etherate), to give corresponding 1, 6-anhydro derivatives.     

Reaction of aminals of conjugated unsaturated ω-dimethylaminoaldehydes with 1,2-, 1,3-, 1,4-, 1,5-, and 1,6-diketones

The condensation of aminals of -dimethylaminoacrolein and 5-dimethylaminopenta-2,4-dienal with cyclic and acyclic 1,2-, 1,3-, 1,4-, 1,5-, and 1,6-diketones was studied. A series of previously unknown bis(,-dimethylaminopolyenyl)diketones was synthesized; their structures were established by means of¹H and¹³C NMR spectroscopies. The electron absorption spectra were employed to study the mutual influence of -aminopolyene chromophores separated by two C=O groups.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1235–1241, July, 1993.     

Synthesis of binuclear complexes of PdCl2 with chiral α,α′-diamino-meta-xylene dioximes H2L1, H2L2, and H2L3, the derivatives of the terpenes (+)-3-carene, (R)-(+)-limonene, and (S)-(−)-α-pinene. Crystal structure of [Pd2(H2L1)Cl4]

Chiral α,α′-diamino-meta-xylene dioximes H₂L¹, H₂L², and H₂L³ were obtained from the naturally occurring terpenoids (+)-3-carene, (R)-(+)-limonene, and (S)-(?)-α-pinene, respectively. Reactions of these ligands with PdCl₂ gave the diamagnetic complexes Pd₂(H₂L¹)Cl₄ (I), Pd₂(H₂L²)Cl₄ (II), and Pd₂(H₂L³)Cl₄ (III). According to X-ray diffraction data, the crystal structure of complex I consists of acentric binuclear molecules [Pd₂(H₂L¹)Cl₄]. The coordination polyhedron PdN₂Cl₂ is a square distorted in a tetrahedral manner (trapezium) made up of two N atoms of the tetradentate bridging cyclic ligand H₂L¹ and two Cl atoms. The fragments PdCl₂ in the complex are cis to each other. According to the ¹H NMR spectra of complexes I–III in CDCl₃, the organic ligands are coordinated through the N atoms; in solution, the complexes exist in several forms.     

5-芳酰氨基-2-苯基-2H-1, 2, 4-噻二唑-3-酮的合成

用1-芳酰基-5-苯基-2-硫代双脲与溴进行氧化成环反应制备了九个新的5-芳酰氨基-2-苯基-2H-1, 2, 4-噻二唑-3-酮, 相应的1-芳酰基-5-苯基-2-硫代双脲可以通过苯基脲与酰基异硫氰酸酯加成制得。     

Synthesis of protected （2S,4R）-2-amino-4-methyldecanoic acid,a proposed component of culicinins

The protected （2S,4R）-2-amino-4-methyldecanoic acid, a proposed component of culicinins has been synthesized over 10 steps and in total 28% yields using Wittig reaction and Schollkopf amino acid synthesis as key steps.     

Asymmetric Synthesis of (-)-(2R,3R,6S)-Irnigaine

Introduction　　Asarelativelynewmemberofnaturalalkaloidswith2 ,6 disubstituted 3 piperidinolskeleton ,irnigaine 1wasisolatedfromthetubersofArisarumVulgare (Araceae)in1995byMelhaouiandBode .1Itsstructureandrelativeconfigurationswereelucidatedby1HNMRstudiesandtheabsoluteconfigurationwasproposedonthebasisofitsopti calrotation .1Soonafterthen ,Meyerandhisco workersreportedthefirstsynthesisof (- ) (2R ,3R ,6S) irni gaineandtheconfigurationconfirmation .Althoughtheirsynthesisroutewasshortan…     

Convenient synthesis of （2S,3R,4R,5S,6R）-2-（3-（4-ethylbenzyl）-4- chlorophenyl）-6-（hydroxymethyl）-tetrahydro- 2H-pyran-3,4,5-triol

A convenient approach for the preparation of （2S,3R,4R,5S,6R）-2-（3-（4-ethylbenzyl）-4-chlorophenyl）-6-（hydroxymethyl）- tetrahydro-2H-pyran-3,4,5-triol I is developed. The target compound via four steps is synthesized from 4-bromo-2-（bromomethyl）- 1-chlorobenzene and the isomers of undesired ortho-products were avoided during the preparation.     

Synthesis,reactions, and antimicrobial activity of 2-cyano-N′-(4-(2-oxo-2-phenylethoxy)benzylidene)acetohydrazide derivatives

Knӧvenagel condensation of the starting 2-cyano-N′-(4-(2-oxo-2-phenylethoxy)-benzylidene)acetohydrazide with different aromatic aldehydes produced the comparable arylidenes derivatives. Else way, 2-cyano-N′-(4-(2-oxo-2-phenylethoxy)-benzylidene)-acetohydrazide condensed with o-hydroxybenzaldehydes affording the respective chromenes which latter underwent acid hydrolysis giving the oxo-chromenes analogues. Moreover, the reaction of 2-cyano-N′-(4-(2-oxo-2-phenylethoxy)benzylidene)acetohydrazide with istain yielded the respective indeno[2,1-b]furan derivative that was converted to its oxo-analogue through acid hydrolysis. The treatment of 2-cyano-N′-(4-(2-oxo-2-phenylethoxy)benzylidene)acetohydrazide with α-halocompounds produced the relevant thiazoles. The enamine 2-cyano-3-(dimethylamino)-N′-(4-(2-oxo-2-phenylethoxy)benzylidene)acrylohydrazide underwent nucleophilic substitution reaction with guanidine hydrochloride followed by heterocyclization to get the relative aminopyrimidine. Contrarily, the reaction with various 4-arylazo-3,5-diaminopyrazoles provided the relative pyrazolo[1,5-a]pyrimidines. The antimicrobial investigation was carried out for some of the newly synthesized compounds using agar well diffusion method.     

Conversions of 2-α-chloroalkylbenzimidazoles

Upon interaction with caustic in a DMSO medium, 2-chloromethylbenzimidazoles are subjected to cyclodimerization, forming 5H,12H-pyrazino[1,2-a:4,5-a]bis-benzimidazoles; in the presence of nucleophiles (ammonia, amines, anions of -diketones), under the indicated conditions, the products are the corresponding substituted amines or derivatives of pyrrolo[1,2a]benzimidazole.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 664–672, May, 1993.     

Synthesis,spectroscopic characterization,thermal, and photostability studies of 2-(2′-hydroxy-5′-phenyl)-5-aminobenzotriazole complexes

Three Mn(II), Co(II), and Cu(II) new transition metal complexes of the fluorescence dye: 2-(2′-hydroxy-5′-phenyl)-5-aminobenzotriazole/PBT derived from o-aminophenol and m-phenylenediamine have been synthesized. The structural interpretations were confirmed from elemental analyses, magnetic susceptibility and molar conductivity, as well as from mass, IR, UV–Vis spectral studies. From the analytical, spectroscopic, and thermal data, the stoichiometry of the mentioned complexes was found to be 1:2 (metal:ligand). The molar conductance data revealed that all the metal chelates are non-electrolytes and the chloride ions exist inside the coordination sphere. The thermal stabilities of these complexes were studied by thermogravimetric (TG/DTG) and the decomposition steps of these three complexes are investigated. The kinetic parameters such as the energy of activation (E*), pre-exponential factor (A), activation entropy (ΔS*), activation enthalpy (ΔH*), and free energy of activation (ΔG*) have been reported. Photostability of phenyl benzotriazole as fluorescence dye and their metal complexes doped in polymethyl methacrylate/PMMA were exposed to UV–Vis radiation and the change in the absorption spectra was achieved at different times during irradiation period.