REACTION OF AROMATIC NITRO COMPOUNDS WITH ELEMENTAL SULFUR IN LIQUID AMMONIA AND AMINES

Abstract

Aromatic nitro compounds were reduced with elemental sulfur in liquid ammonia and in amines, yielding the corresponding anilines. However, introduction of a substituent on the benzene ring or variation of the amine changed somewhat the pattern of this reaction. For example, 4-nitrotoluene (3) and 4-cyanonitrobenzene (6) were found to give not only the corresponding reduced products but also 4,4′-dicyanodiphenyl disulfide (10), formed by replacement of the nitro group, in addition to 4-cyanoaniline (9) in the reaction with elemental sulfur in liquid ammonia. Probable mechanisms of these reactions are discussed in the light of new knowledge on the similar reactions of elemental sulfur.     

THE CHEMISTRY OF OPTICALLY ACTIVE SULFUR COMPOUNDS PART III

Abstract

The chemistry of optically active sulfur compounds has proven to be one of great interest and challenge as demonstrated by the prolific publications in this area. An ever larger number of different types of compounds with sulfur as center of chirality are being synthesized and it is expected that in future publications additional members of this group will be described. Thus far the following chiral sulfur compounds have been prepared:     

New Synthetic Reactions Contributed by Sulfur

Abstract

Eighteen kinds of new convenient synthetic reactions respectively contributed by divalent sulfur (7), sulfoxide (7) and sulfone (4) are shown.     

Syntheses of Polythioethers Tethered with Bulky Aryl Groups and Their Complexation with Late-Transition Metals

Abstract

New types of o-phenylene-bridged polythioethers tethered with extremely bulky aryl groups at their terminal sulfur atoms, such as TbtS(o-Phen)S(o-Phen)S(o-Phen)STbt (1) and TbtS(o-Phen)S(o-Phen)SS(o-Phen)S(o-Phen)STbt (2) (Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl, o-Phen = o-phenylene), were synthesized and subjected to the complexation with several kinds of late-transition metals. In the case of polythioether 1, the reaction with RhCl₃·3H₂O in benzene/EtOH resulted in the formation of a unique bimetallic complex, in which a part of ligand 1 is lost and the resulting sulfur atom is directly bound to the other Rh metal center. Interestingly, similar treatment of 1 with IrCl₃·3H₂O afforded ethyl-coordinated mononuclear Ir complex. Furthermore, 1 underwent complexation with Na₂PdCl₄ in EtOH to give the corresponding square planar dichloropalladium complex coordinated with two inner sulfur atoms of 1, while the S₆-ligand 2 reacted with excess of Pd(PPh₃)₄ in benzene to afford a quite interesting trinuclear Pd complex multi-step metal insertion reactions.     

A NEW METHOD FOR PREPARATION OF β-LACTAM SULFOXIDES

Abstract

Penicillin sulfoxides (II) are key intermediates in chemical transformations of penicillins to cephalosporins. Oxidation of the sulfur atom in penicillin nucleus (I) to the sulfoxide (II) has been studied and a new economically feasible method developed.     

Synthesis of 14-Aryl-14H-7-thiadibenzo[a,j]anthracene

Abstract

Preparation methods of dibenzoxanthene derivatives are surveyed alongside the synthesis of some of the titled compounds, which are the sulfur analogues of dibenzoxanthenes. Our new procedure for the conversion of phenols to thiophenols was used to prove the structure of such sulfur analogues.     

Sulfur Isotopic Exchange Between Two Thiophosphoryl Compounds

Abstract

Thiophosphoryl compounds are useful sulfur donors in thionation reactions (1,2) leading to P=S –> P=O exchange in thiation reagents. Although the reverse conversions P=O –> P=S are also known, mechanisms of both these types of reactions are not thoroughly studied. The analogy of chemical and isotopic exchange reactions in thiophosphoryl moiety push us to investigate the kinetics of isotopic exchange between two thiophosphoryl compounds.     

Determination of Sulfur Compounds in Air by Chemiluminescence

Abstract

The present review is devoted to applications of chemiluminescence to the analysis of trace sulfur species in air. Determinations of oxidized (sulfur dioxide and sulfite), reduced (hydrogen sulfide, dimethyl sulfide, carbonyl sulfide, carbon disulfide and mercaptans) and/or sulfur compounds in general are described and some practical considerations are discussed. The development of detectors based on chemiluminescence in the aproximately last fifteen years is also reviewed.     

Synthesis and Characterization of Three Coordinate “T-Shaped” Complexes of Tellurium (II) Incorporating a Naphthyl Tellurium Fragment

Several new three coordinate tellurium(II) complexes have been prepared by the addition of dinaphthyl ditelluride (C₁₀H₇)₂Te₂ and a halogen (Br₂ or I₂) to various monodentate ligands known to coordinate through their terminal sulfur or selenium atoms to investigate possible electronic and steric effects associated with a large aryl group. Complexes of the type RTeX(L) are described here [R = naphthyl, X = Br, I, L = thiourea (I (X = Br), II (X = I)), tetramethylthiourea (III), selenourea (IV), tris(dimethylamino)phosphane selenide (V) and N-methylbenzothiazol-2(3H)-thione (VI)]. Evidence of the formation of new complexes is presented through microanalytical data and multinuclear NMR spectroscopy in addition to single crystal X-ray diffraction studies of (I) and (III). Structures are described in detail along with a comparison with related Te (II) complexes.     

A NEW TYPE OF PHOTOCHEMICAL ADDITION REACTION OF ELEMENTAL SULFUR TO OLEFINS

Abstract

Photochemical reactions of elemental sulfur with several olefins were studied. Irradiation of a mixture of elemental sulfur and norbornylene with 3500 Å light afforded 3,4,5-trithiatricyclo[5.2.1.0]decane (1) and 2,3-epithionorbornane (2). Similarly, several thiane derivatives (4–6) were found to be formed by the photolysis of a mixture of cyclohexene and sulfur.     

Polymerization of elemental sulfur with various divinyl and diallyl monomers and properties of the copolymers

Abstract

Polymeric sulfur generated from thermal ROP forms a semi crystalline, intractable solid with poor mechanical properties and is not easy to melt and resists solid processing. Stabilization of diradical polymeric sulfur form can be achieved by reaction with dienes which stabilizes the polymeric sulfur (depolymerization of polymeric sulfur by polymerization with diene co-monomer). The present work demonstrates how the physical properties of the sulfur based copolymer can be tuned by varying the vinylic and allylic modifier. These particular new structurally modified sulfur based copolymers could act as efficient polymer binders for making concrete materials.     

DEHYDROCHLORINATION OF α-CHLORO SULFONES WITH KOH-T-BUOH: KINETIC VS EQUILIBRIUM CONTROL OF THE FORMATION OF α, β-UNSATURATED SULFONES AND THE β-T-BUTOXY AND β-HYDROXY MICHAEL ADDUCTS

Abstract

Inorganic sulfur compounds are used by microorganisms (bacteria, fungi, algae) and plants for assimilation, i.e. biosynthesis of sulfur-containing cell constituents.

Quantitatively, within the biogeochemical cycle of sulfur the utilization of inorganic sulfur compounds in bacterial energy metabolism, i.e. dissimilatory sulfur utilization, is of far higher importance. Reduced sulfur compounds serve as electron donors for photosynthesis and respiration, whereas inorganic sulfur compounds of oxidation levels above sulfide serve as electron donors in anaerobic respiration as well as in fermentation. In still other bacteria reduced sulfur compounds act as protective agents against hydrogen peroxide.     

Selective separation of minor actinides and lanthanides using aromatic dithiophosphinic and phosphinic acid derivatives

A new extractant for the separation of actinide(III) and lanthanide(III) cations, bis(o-trifluoromethylphenyl) phosphinic acid (2) was synthesized. The synthetic route employed mirrors one that was employed to produce the sulfur containing analog bis(o-trifluoromethylphenyl) dithiophosphinic acid (1). Classic radiochemical methods and absorbance spectroscopy were used to study the coordination chemistry of the Am-dithiophosphinic acid and Am-phosphinic acid complexes.     

Synthesis and characterization of mononuclear copper(II) and cadmium(II) complexes with di-(2-picolyl)sulfur

The reaction of Cu(ClO₄)₂·6H₂O and Cd(ClO₄)₂ with di-(2-picolyl)sulfur (dps) leads to the formation of mononuclear complexes [Cu(dps)(H₂O)(ClO₄)](ClO₄) (1) and [Cd(dps)₂](ClO₄)₂ (2). The crystal structure of 1 exhibits a distorted square pyramidal geometry, coordinated by one sulfur and two nitrogen atoms from the dps ligand, one water molecule and one perchlorate oxygen atom. For 2, the environment around cadmium atom is in a distorted octahedron with four nitrogen and two sulfur atoms from the dps ligand. Cyclic voltammetric data show that complexes undergo two waves of a one-electron transfer corresponding to M(II)/M(III) and M(II)/M(I) processes. Spectral and electrochemical behaviors of the complexes are also discussed.     

SYNTHESIS OF SULFINES BY ALKYLIDENATION OF SULFUR DIOXIDE

Abstract

The most important route for the preparation of sulfines (thione-oxides) thusfar is that involving the oxidation of thiocarbonyl containing compounds with peroxycarboxylic acid. A new challenging approach to the synthesis of sulfines is the alkylidenation of sulfur dioxide.     

Sulfur-34 as an Internal Standard for the Quantitation of Environmental Sulrur by Combined Gas Chromatography -Mass Spectrometry

Abstract

The quantitative analysis of sulfur by combined gas chromatography-mass spectrometry (GC-MS) can be effected using ³⁴S-enriched sulfur as an internal standard.     

Synthesis and Characterization of Nitrogen Heterocyclic Derivatives Containing Sulfur–Ether and Schiff Base

Abstract

A series of new nitrogen heterocyclic compounds containing sulfur–ether (8a–8f) and Schiff-base (9a–9q) functionalities were synthesized by the reaction of the pharmaceutical lead compound containing both benzimidazole and 1,2,4-triazole rings. The compounds were characterized by ¹H NMR, ¹³C NMR, FT-IR, HR-MS, and ESI-MS.     

STUDIES IN THE HETEROCYCLIC SERIES. IX. SYNTHESIS OF HETEROCYCLIC THIOLS

Abstract

A survey of the chemical literature recently undertaken by us, has revealed that much greater attention is being given nowadays to organo-sulfur compounds. New products containing sulfur have emerged and many of them were isolated from coal, 3 plant, animals' and soil microbes. 6 A great majority of them are, however, man-made and are obtained by intricate but often exciting synthetic procedures which give rise to new reactions, new chemistry and a great variety of potentially useful chemical compounds. These studies led to the synthesis of derivatives of phenothiazine (1)7 the sulfur analog of phenoxazine, and to dithieno(2,3-b: 2′,3′-e)(l,4)thiazine (2)′, cyclopental(1,2-b: 4,3-bf)-dithiophene (3)9 and benzothienoacridine (4) derivatives which are thiophene analogs of phenothiazine, fluorene and benz(c)acridine respectively.     

α,ω-Bis(Dialkylthiophosphoryl)Sulfanes-Products of the Alcoholysis of Sulfur-Rich Phosphorus Sulfides

Abstract

The high solubility of sulfur-rich phosphorus sulfides in CS₂-especially in the range S:P=2.7 to 4-is the motive for new investigations on this system. DEMARCQ¹ suppsed the existence of “molecular products”, but he coulds not prove it by spectroscopic and chemical methods. As we have found the formation of α, ω-bis (fluorodithicphosphoryl) oliqosulfanes at the nucleophilic degradation of phosphorus sulfides with fluorides gives no proof for the existence of oligosulfane bridges in the sulfur-rich phosphorus sulfides. On the reaction of P₄S₁₀, elementary sulfur and alka-lifluorides the same products are formed. Sulfur-rich phosphorus sulfides and alcohols also react to mixtures of α,ω-bis (dialkylthiophosphoryl)sulfanes. But these compounds are not obtained by the reaction of P₄S₁₀ and sulfur with alcohols.     

The Behavior of Certain Coumarins and Furocoumarins Toward Sulfur Reagents

The behavior of 4-hydroxycoumarin (1), 7-hydroxycoumarin (2), 4-hydroxy-bergapten (3), and 4-hydroxyisopimpinellin (4) toward sulfur reagents, namely, thionyl chloride, phosphorus pentasulfide, thiolacetic acid, and Lawesson's reagent (5), was studied. The nature of products in each case depended upon the type of reactants and reaction conditions. Possible reaction mechanisms were considered, and structural elucidations of the new products were based upon compatible elementary and spectroscopic evidences.