ELEGANT SYNTHESIS OF SOME NOVEL SPIRO [BENZOTHIAZEPINE-INDOLE] DERIVATIVES

Abstract

The synthesis of some novel sulfur-containing spiroindole derivatives is reported, 2,3-Dihydrospiro [cycloalka[3,4][1,5] benzothiazepine-2,3′-[3H]indole]-2′-(1′H)-ones (V) were prepared by the reaction of 1,3-dihydro-3-(2-oxocycloalkylidene)indole-2(1H)-one (II) with 2-aminothiophenol in dry toluene. The compounds have been characterized on the basis of elemental and spectral studies.     

SYNTHESIS AND SPECTROSCOPIC STUDIES OF SOME FUNGITOXIC ORGANOLEAD(IV) COMPLEXES OF SULFUR AND NITROGEN DONOR LIGANDS

Abstract

Some organolead(IV) complexes derived from biologically active sulfur and nitrogen donor ligands have been synthesized and characterized by elemental analyses, molecular weight determinations and conductivity measurements. The trigonal bipyramidal and octahedral geometries for these complexes have been proposed on the basis of electronic, infrared and NMR (¹H and ¹³C) spectral evidences. The antifungal activity of some of the ligands and their complexes have also been evaluated against Fursarium oxysporum SCW. ex Frics f. sp. Ciceri (Pedwick) subram.     

STUDIES ON THE SYNTHESIS OF THIOLS AND THEIR S-SUBSTITUTED DERIVATIVES

Abstract

Aromatic thiols belong to a group of not yet sufficiently explored compounds. The presence of an active hydrogen atom makes it possible to conduct various chemical conversions and to obtain new S-substituted derivatives.     

NMR spectra of 1,3,5-triazines with fluorinated substituents

The NMR spectra of a series of 1,3,5-triazines (1) in which one or more of the substituent groups are fluorinated are described, and the results are discussed in terms of bonding and geometry of the molecules. Remote effects of unsymmetrical substitution are observed in the fluorine-19 and carbon-13 spectra, in some molecules indicating restricted rotation about the bond joining an amino group to a ring carbon.     

SYNTHESIS,NMR AND MOLECULAR MODELING STUDY OF 4,9a-DIARYL-9,9a-DIHYDRO 1H-[1,4]THIAZINO[4,3-a][1,3]BENZIMIDAZOLES

A series of substituted 4,9a-diaryl-9,9a-dihydro-1H-[1,4]thiazino[4,3-a][1,3]benzimidazoles was prepared in good yields from the reaction of bis(aroylmethyl) sulfides with ortho-phenylenediamine in glacial acetic acid under reflux and under microwave irradiation. Microwave irradiation is found to accelerate the reaction, besides giving better yield in the case of the thiazinobenzimidazoles with electron-withdrawing groups in the aryl rings than the thermal reaction.     

13C NMR STUDY OF SUBSTITUENT EFFECTS IN 1,2,4-OXADIAZOLE AND 1,2,4-THIADIAZOLE DERIVATIVES

¹³C chemical shifts of C═N, C═O and C═S carbons of 3,4-disubstituted-1,2,4-oxadiazole-5-ones(thiones) and 3,4-disubstituted-1,2,4-thiadiazole-5-ones have been determined in CDCl₃ solution. Exceptionally good Hammett correlations of ¹³C NMR chemical shifts of these carbons with σ were obtained. The negative ρ values observed (inverse substituent effects) indicate π-polarization of the C═N, C═O and C═S bonds. As expected, the long distance C═O and C═S ¹³C chemical shifts were found less susceptible to substituent-induced electronic changes.     

New deuterium isotope effects on C and F chemical shifts across intramolecular hydrogen bonds of non-resonance assisted systems

A series of thioanilides and corresponding anilides, some of which contain fluorinated phenyl rings, have been synthesized as model compounds. They all contain rather strong intramolecular hydrogen bonds, the strength of which varies. Deuterium isotope effects on ¹⁹F and ¹³C chemical shifts due to deuteriation at the NH proton show interesting new long-range isotope effects on chemical shifts that may be related to the existence of an intramolecular hydrogen bond and to transmission of the isotope effect due to an electric field effect. Deuterium isotope effects on chemical shifts report on variations in hydrogen bonding, for example, as a function of changes in substituents or temperature. Deuteriation leads to a strengthening of the hydrogen bond.     

几个新型二茂铁衍生物的合成

二茂铁及其衍生物作为油类消烟剂、燃速催化剂等已得到应用,在药物、合成材料等方面亦具有应用前景。文献曾报道含二茂铁基β-二酮的合成及以它为配体的金属配合物。此类配合物均含两个以上金属原子,它们在有机合成中具有独特的催化活性。 我们将二茂铁甲酰丙酮分别与水扬酰肼、异菸肼、乙二胺及硫代氨基脲在甲醇或甲醇-水介质中进行缩合反应,合成了4个新型二茂铁衍生物,它们含有三个或四个配位功能基团,可作为多齿配体用于金属有机配合物的合成。衍生物的合成路线如下:     

STUDIES ON ORGANOPHOSPHORUS COMPOUNDS PART IX.1 THE ACTION OF Di-, TRIALKYL PHOSPHITES AND THIOL ACIDS ON SOME ENAMINOLACTONES

Abstract

Di-, and trimethylphosphites react with enaminolactone, 4, only in methanol to give N-benzoyl-3-phenyl-3-phosphonoalanine-trimethylester (7) in good yields. Diphenylphosphinodithioic acid also reacts with 4 to give N-benzoyl-3-phenylcysteine-methyl ester-diphenylphosphinodithioate (9). A mechanism is proposed to account for the formation of 7. Compatible analytical and spectroscopic results were obtained for the new compounds.     

SYNTHESIS OF THE FIRST BENZODISELENAGERMOLES AND ONE SPIROBISDISELENAGERMOLE

Abstract

The first examples of compounds R¹R²GeSe₂C₆H₄R³ (R¹,R²=CH³ C₂H₅, C₃H₂, n-C₄H₉, i-C₅H₁₁, Ph, p-CH₃Ph. R³=H, CH₃, OCH₃) were easily obtained (40–80% yield) from electrophilic cleavage of diselenophenylene zirconocenes by dialkyl or diaryl dichlorogermanes. The synthesis of a spirodi-selenagermole was achieved in the same way using germanium tetrachloride. Analytical data, ¹H and ⁷⁷Se NMR. mass spectra are perfectly consistent with the expected structures.     

钌取代的钨锗和钨硼杂多化合物的合成与表征

本文合成了Keggin结构的［GeW₁₁O₃₉(Ru·OH₂)］^5-和［BW₁₁O₃₉(Ru·OH₂)］^6-杂多阴离子的四丁基铵盐。通过紫外-可见、红外光谱、核磁共振、顺磁共振和循环伏安法对上述化合物进行了表征。结果表明Ru(Ⅲ)处于一个八面体弱场中，Ru(Ⅲ)的顺磁性和核四级矩对 ¹⁸³W的化学位移和强度有明显的影响，其电化学还原与W(Ⅳ→Ⅴ)相关。Ru(Ⅲ)填充了缺位杂多阴离子的空位，但仍然保持Keggin结构。     

Structure of red and orange fluorescein

The structures of colorless, red, and yellow-orange fluorescein have been investigated by a combination of solution and solid state¹³C NMR. It is demonstrated that the three forms have lactonic, zwitterionic, and quinoid structures, respectively. Conflicting X-ray, NMR, and IR structural evidence is discussed for samples of red fluorescein which cannot readily be obtained in definite crystalline form. It is concluded that solid-state¹³C NMR spectroscopy is superior by revealing primarily the molecular structure but being fairly insensitive toward lattice variations.The Editors regret the long delay in having this paper printed due to an unfortunate administrative error.     

SYNTHESIS AND TRIBOCHEMICAL BEHAVIOUR OF SOME MONOTHIOPHOSPHORIC ACID DERIVATIVES

Abstract

Diisopropylphosphite reacts with sulphur and ammonia to form ammonia monothiophosphoric acid-diisopropylester which, by subsequent reaction with different monochloroacetic acid esters, yields the corresponding monothiophosphoric-acid-O,O-diisopropyl-S-carboalkoximethylesters. These compounds show different wear- and friction-reducing properties in lubricating oils. The tribochemical activity at higher temperatures increases with the chain length of the carboxylic ester group. Auger electron spectroscopy (AES) of the worn metal surface shows that the wear reducing properties correspond with the phosphorus content in the metal surface produced by tribofragmentation of the monothiophosphates. A possible explanation of this effect is discussed.     

SYNTHESIS AND SPECTRAL CHARACTERIZATION OF DIETHYL 2-[ARYL(4-ARYL-1,2,3-SELENADIAZOL-5-YL)METHYL]MALONATE

Synthesis and characterization of several diethyl 2-[aryl(4-aryl-1,2,3-selenadiazol-5-yl)methyl]malonates are reported.     

Analysis of F and C NMR spectra of tetrafluorophthalic anhydride and its derivatives

¹⁹F and ¹³C NMR spectra of perfluorinated compounds (i.e., tetrafluorophthalic anhydride, its hydroxyl- and amino-derivatives, N-pentafluorophenyltetrafluorophthalimide, and hexafluoroindan-1,3-dione) were analysed. Different signals in NMR spectra were assigned based on the analysis of spin-spin coupling constants. All assignments made were further confirmed by density functional theory (DFT) calculations of ¹³C chemical shifts and J_C,F coupling constants.     

Solid state13C NMR spectra of metal carbonyl clusters

The solid state¹³C NMR spectra of four¹³CO enriched carbonyl clusters having a tri-iron metallic core have been analyzed to provide structural and dynamic information. In Fe₃(CO)₁₂ (1), the high temperature spectra suggest the occurrence of large amplitude motions of the CO groups around their position at the vertexes of the coordination polyhedron in addition to the motion involving the Fe₃-triangle previously detected in the VT-¹³C MAS spectra.¹³C and³¹P NMR data of Fe₃(CO)₁₁PPh₃ (2) indicates the presence of one molecule in the asymmetric unit in apparent disagreement with the previously reported X-ray data. Furthermore, we show that structural information can be obtained from the chemical shift tensor components readily available from the analysis of the spinning sideband manifold.     

19F, 13C NMR analysis of an oxygen carrier,perfluorotributylamine, and perfluoropentanoic acid

NMR relaxation measurement of perfluorocarbons (PFCs), such as perfluorotributylamine (FTBA), is a convenient method for the determination of oxygen concentrations in tissues and tumors. Previous relaxation studies of FTBA used different ¹⁹F NMR assignments causing some confusion. Fluorine‐detected ¹⁹F, ¹³C HMQC and HMBC and selectively ¹⁹F‐decoupled ¹³C NMR provided unequivocal ¹⁹F and ¹³C assignments for FTBA and perfluoropentanoic acid (FPA). Based on those assignments, ¹³C spin–lattice relaxation time constants (T₁) and effective correlation times for FTBA and FPA are reported and discussed. Copyright © 2003 John Wiley & Sons, Ltd.     

Quantitative F NMR method validation and application to the quantitative analysis of a fluoro-polyphosphates mixture

Quantitative ¹⁹F NMR (QNMR) was developed and employed to determine the amounts of four kinds of fluoropolyphosphates (FPPs) in a mixture containing sodium monofluoro-phosphate (MFP), sodium monofluoro-dipolyphosphate (MFDPP), sodium monofluoro-tripolyphosphate (MFTPP) and sodium difluoro-tripolyphosphate (DFTPP). The amounts of these ingredients cannot be measured by high-performance liquid chromatography (HPLC) because no high-purity standard samples are available. The main parameter “delay time (d1) between two scans” of affecting the response of NMR signal was determined by measuring longitudinal relaxation time (T1) to be 25 s. By using NaF as an internal reference to measure the amount of MFP solution with known concentration and then to compare the deviation between experiment value and real value, a simple and effective approach for checking out the validity of ¹⁹F QNMR method was carried out. Six experiments with different mole ratios of NaF/MFP over 200 times were repeated and the relative standard deviation (R.S.D.) of results is less than 2.0%, the limit of detection of ¹⁹F QNMR can reach to 1.0 mmol/L. NaF was used as an internal reference for the quantitative analysis of FPPs mixture. The amount of each FPP in FPPs mixture obtained by ¹⁹F QNMR was calculated and the R.S.D.s of results were less than 4.81%.     

13C NMR spectroscopy of tautomeric conversions in imidazole compounds

A study has been made of¹³C NMR spectra of several series of imidazoles and their salts in solution and in the solid state. It has been shown that in compounds containing a pyridine ring, prototropic tautomerism on the NMR time scale may be retarded. The possible mechanism of these processes is discussed.V. I. Vernadskii Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, 11795 Moscow. Torino University, Italy. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 299–308, February, 1992.     

ELECTROCHEMICAL ISOMERIZATION OF SULFINE

Abstract

Electrochemical isomerization of 1-phenyl-2, 2-dimethylpropane-1-thione S-oxide (phenyl-t-butylsulfine, E and Z form, 1a and 1b) was studied. Anodic isomerization of 1a gave the two isomers of the sulfine only, but cathodic reductive isomerization of 1a gave pivalophenone and 1-cyano-2-phenyl-3, 3-dimethyl-1-butene in addition to the E and Z isomers. This is the first example of an electrochemical reaction of a sulfine.