Diinsertion of fluorenylidene into a sulfur-sulfur bond of diaryl disulfides

Upon irradiation (>340 nm) of a benzene solution of diazofluorene with di-p-tolyl- or di-p-anisyl disulfide, the corresponding 9,9′-bis(arylmercapto)bifluorenyl was afforded in moderate to good yield accompanied by formation of 9,9′-bis(arylmercapto)fluorene. The major reaction pathway is considered to be a disulfur ylide formation followed by two times of successive Stevens rearrangement or by concerted electron redistribution via [2,3]sigmatropic rearrangement.     

Reaction of methyl thiocarbamate with nonsubstituted malonyl dichloride. Effect of conditions on reaction direction

The reaction of methyl thiocarbamate with malonyl dichloride at low temperatures provides an N-substituted thiocarbamate, whereas prolonged boiling in high-boiling solvents gives rise to 4-hydroxy-2-(methylsulfanyl)-6H-1,3-oxazin-6-one that was also prepared by treatment of the N-substituted thiocarbamate with malonyl chloride in toluene and chlorobenzene.     

异龙脑甲醚断裂反应的研究

研究了异龙脑甲醚在三氯化铁 /乙酸酐存在下的断裂反应 ,并详细讨论了三氯化铁用量、反应时间和反应温度对断裂反应的影响。     

Reactions of benzeneselenyl and benzenesulfenyl chlorides with syn‐ and anti‐9,9′‐bibenzonorbornenylidenes

Reaction of syn‐9,9′‐bibenzonorbornenylidene (1a) with benzeneselenyl chloride produced vic‐dichloride (4) exclusively, which corresponds to the cis‐addition product of 1a with molecular chlorine, with retention of the original alkene configuration. Moreover, the reaction of anti‐9,9′‐bibenzonorbornenylidene (1b) with benzeneselenyl chloride gave the same vic‐dichloride (4) exclusively with inversion of the original alkene configuration. No expected benzeneselenyl chloride adducts were formed in both cases. On the other hand, reactions of 1a and 1b with benzenesulfenyl chloride only resulted in the syn–anti isomerization of the alkenes without any adduct formation. Mechanisms of these reactions are discussed in some detail. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:625–629, 2001     

On the reaction of tin dichloride and of metallic tin with hydrochloric acid in the presence of alkenes. The question of trichlorostannane(IV) or chlorostannate(II) intermediates.

Studies of the reaction of tin dichloride and of metallic tin with hydrochloric acid gas in diethyl ether are described. On the basis of spectroscopic and analytical data it is concluded that the product is not to be regarded as a tin-hydrogen bonded analog of chloroform, viz. trichlorostannane(IV), and the formation of an equilibrium mixture of hydrogen trichlorostannate(II) and dihydrogen tetrachlorostannate(II) is tentatively suggested. The complexes slowly decompose as a result of diethyl ether cleavage, yielding ethanol and ethyl chloride, together with traces of ethyltin trichloride.The mechanism of addition of the complexes to methyl acrylate is discussed in terms of a 1,4-addition involving initial protonation of oxygen. Reaction of the resulting β-carbomethoxyethyltin trichloride with tin or with zinc gives rise to mixtures of bis(β-carbomethoxyethyl)tin dichloride and tris(β-carbomethoxyethyl)tin chloride Similar reactions were observed for the first time with methyltin trichloride, the reaction with zinc being extremely fast at room temperature.     

Oxidation-alcoholysis of organosilyl- and organogermyl-substituted ferrocenes in the presence of ferric ions

Eleven ferrocene derivatives bearing the MM (M = Si and/or Ge) substituent bonded directly to the ring have been found to undergo alcoholysis at the MM linkage in the presence of either ferric chloride or ferricenium tetrachloroferrate. It is suggested that the oxidation-reduction process between the ferrocene derivatives and ferric ions gives rise to the corresponding substituted ferricenium ions, which, in turn may readily undergo a nucleophilic attack by alcohol at the adjacent highly polarized MM bond. The reaction is thus very similar to the acid-catalyzed alcoholysis of these ferrocene derivatives.     

Intramolecular catalysis and cyclization in the reaction of α,ω-diaminooligomethylenes with bifunctional sulphonyl chloride. Effect of chain length on polycondensation reaction

As an elementary reaction of polycondensation reactions, rates of the reaction of 1,5-naphthalenedisulphonyl dichloride, a bifunctional fluorescent reagent, with excess α,ω-diaminooligomethylenes were measured by fluorometry in dilute solution. The rate constant, corresponding to that for the reaction of the first step of the polycondensation between the disulphonyl dichloride and the diamines, depended remarkably on the chain length of the diamines. By using 5-dimethylamino-1-naphthalenesulphonyl chloride, a monofunctional fluorescent reagent, and α-aminooligomethylenes, rates of model reactions between the monoamines and the monosulphonyl chloride, the diamines and the monosulphonyl chloride, as well as the monoamines and the disulphonyl dichloride were measured by fluorometry. The remarkable chain length dependence is explained by intramolecular catalysis by the primary amino group.     

Sur la transformation du β-nitrostyrène sous l'action du chlorure d'acétyle en présence d'un chlorure métallique

While β-nitrostyrene yields only hydroxymic or hydroxamic acid derivatives by treatment with acetyl chloride in the presence of zinc, tin, titanium or aluminium chloride, it also gives 3-chloro 2-indolinone and a 5-acetyl derivative of the latter, when the reaction is carried out with ferric chloride. The procedures of this reaction are examined, and a mechanism is suggested.     

Computational study of the catalytic synthesis of 5‐nitro‐1,2,4‐triazol‐3‐one

In this study, 5‐nitro‐1,2,4‐triazol‐3‐one (NTO) was theoretically synthesized from urea via chlorination followed by amination, formylation, and nitration under aqueous and gaseous environments based on experience of experimental methods, and metal chlorides and metal oxides were used as catalysts to promote reaction. Reaction routes closely related to experimental processes were successfully constructed, and the corresponding energy barriers were estimated for each elementary reaction. Reaction conditions distinct from those reported in the literature (including the adoption of aluminum chloride, ferric chloride, aluminum oxide, ferrous oxide, and chromium oxide catalysts, the use of nitric acid and dinitrogen pentoxide as nitration agents, and adjustment of the reaction temperature) were used in corresponding reaction systems, and the modeling results suggested that ferric chloride is a good catalyst for the chlorination reaction, ferrous oxide is suitable for catalyzing amination, formylation, and nitration, and nitric acid is the better agent for nitration. Estimates of the comparable energy barriers for each reaction stage were considered to imply more feasible pathways for NTO synthesis. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

Increased rates of initiation of polymerization by 4-4′-dicyano-4-4′-azopentanoic acid in the presence of ferric salts

The initiation of the polymerization of acrylamide by 4-4′-dicyano-4-4′-azopentanoic acid in aqueous solution has been studied kinetically at 25°C. Ferric chloride and ferric sulfate were used to terminate polymerization so that rates of initiation could be calculated from the rates of production of ferrous iron. Velocity coefficients at 25°C. for the initiation reaction were found to be (25.7 ± 2.8) × 10^?7 sec.^?1 for the ferric chloride terminated reaction and (73.6 ± 0.6) × 10^?7 sec.^?1 for the ferric sulfate-terminated polymerization. The value reported for the initiation reaction when acrylamide is polymerized in the absence of metal salts is 1.29 × 10^?7 sec.^?1. Velocity coefficients for the termination reaction have been calculated from the overall rates of polymerization obtained with ferric salts present. In the case of the ferric chloride-terminated reaction, it has been shown that the rate of polymerization is reduced by increasing the total concentration of chloride ions. Termination velocity coefficients at 25°C. for the inner sphere complexes FeCl²⁺·5H₂O and FeSO₄⁺·4H₂O have been calculated to be 18.9 × 10⁴ and 7.98 × 10⁴ l./mole-sec., respectively. The dependence on the concentration of ferric chloride of the molecular weights of the polymers produced has also been considered.     

Influence of FeCl3‐modified chloroaluminate ionic liquids on long‐chain alkenes alkylation

The influence of anhydrous ferric chloride on the catalytic properties of chloroaluminate ionic liquids catalyst for Friedel–Crafts alkylation was investigated. The catalysts were characterized by Fourier‐transform infrared (FT‐IR) (acetonitrile molecule as probe), specific gravity, and ²⁷Al NMR. Besides, the effect of the mass ratio of FeCl₃ to AlCl₃, catalysts dosage, toluene/olefin molar ratio, reaction temperature, and reaction time on long‐chain alkenes alkylation were investigated thoroughly. And bromine value and high‐performance liquid chromatography (HPLC) were employed as the evaluation method for alkylation products. It was observed that the addition of anhydrous ferric chloride results in improvement in terms of Lewis acid and its catalytic recyclability. Among these catalysts studied, the catalyst modified with 1.0 wt.% anhydrous FeCl₃ showed the best catalytic performance in terms of yield and stability, which can be attributed to the formation of new stronger acidic ions [Al₂FeCl_l0]^? when the added ferric chloride reacts with acidic ions [Al₂Cl₇]^?.     

Preparation and photocrosslinking behaviors of polyesters derived from trans-2,2′-dihydroxystilbene

The monomer, trans-2,2′-dihydroxystilbene (DHS), has been prepared by asymmetric photocleavage (254 nm) of coumarin dimer acid derived from coumarin dimer. Four new polyesters are successfully synthesized by interfacial polycondensation of the DHS with adipoyl chloride, azelaoyl chloride, sebacoyl chloride, and dodecanedioyl dichloride, respectively. The reduced viscosities of the polyesters decrease from 0.32 to 0.11 dL/g as the number of methylene unit in diacid chlorides increases from 4 to 10. From DSC investigation, it is found that the polyesters are semi-crystalline polymers with T_m = 39–192°C. Under 350 nm light, photocrosslinking behavior in solution and film-state is investigated by UV spectral change with irradiation time (350 nm). The photoreactive stilbene chromophores in the main chain dimerize to form cyclobutane derivatives, and lead to crosslinking of the polyesters. Photosensitivity in the film state has also been evaluated by their characteristic curves. Polyester from dodecanedioyl dichloride ( 5d ) exhibits the highest initial reaction rate and ultimate crosslinking ratio. © 1995 John Wiley & Sons, Inc.     

A facile synthesis of 2‐amino‐1,3‐selenazole by reaction of N,N‐unsubstituted selenourea with ketone

2‐Dialkylamino‐1,3‐selenazoles were yielded by the reaction of N,N‐unsubstituted selenoureas with ketones in the presence of ferric chloride. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:88–92, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20180     

漆酚铁聚合物的制备及性能研究

以生漆和三氯化铁反应制备漆酚铁聚合物,用红外光谱、涂膜鲜映性仪和光泽度仪等对聚合物结构和漆膜性能进行表征.结果表明,反应温度65℃,反应时间3h,漆酚和三氯化铁物质的量比为8∶1,所生成的漆酚铁聚合物性能较好.     

The effects of some transition-metal compounds on the flame retardance of poly(styrene-co-4-vinyl pyridine) and poly(methyl methacrylate-co-4-vinyl pyridine)

Several copolymers of both styrene and methyl methacrylate with 4-vinyl pyridine have been prepared and modified by coordination with the transition-metal compounds vanadium acetylacetonate (VO[acac]₂), vanadyl dichloride (VOCl₂) and ferric chloride. The flame-retardant effects of these modifications have been assessed by measurements of limiting oxygen indices, by thermogravimetric analysis, and by examination of chars by scanning electron microscopy. Effects on mechanical properties have been assessed by dynamic mechanical thermal analysis. The limiting oxygen indices of the modified polymers are significantly higher than those of the parent polymers, and the production of considerable amounts of rigid, intumescent chars suggests predominantly condensed-phase mechanisms of flame retardance.     

Determination of ultramicro amounts of sulphate as methylene blue—I The colour reaction

Sulphate may be determined spectrophotometrically as methylene blue after reduction to sulphide, which is allowed to react with p-aminodimethylanuine and ferric iron to form the dye. This paper deals with the colour reaction.

The standard method for the colour development proposed is founded on an investigation of the following variables: hydrogen sulphide losses, acidity at reaction and measurement, reagent concentrations, temperature at reaction and measurement, concentration of traces of heavy metals, time, and air-oxidation. Previously found deviations from Beer's law are confirmed and discussed. The yield of the reaction is determined.     

Studies on Lewis acid-mediated intramolecular cyclization reactions of allene-ene systems

The Lewis acid-mediated reactions of allene-ene compounds, derived from 3-methylcitronellal or dimethyl malonate, were carried out using various Lewis acids such as ethylaluminum dichloride, diethylaluminum chloride, titanium chloride, zinc chloride etherate, or boron trifluoride etherate, affording unexpectedly intramolecular [2+2]cycloaddition products under some particular reaction conditions without any formation of intramolecular ene reaction products.     

Thermolysis of the phenyltin chlorides,PhxSnCl4–x, (x=1−3): Products and pathways

The thermal degradation of triphenyltin chloride, diphenyltin dichloride and phenyltin trichloride has been studied by pyrolysis at 375°C in sealed tubes for various time periods. In all cases, biphenyl and tin(II) chloride are produced. For both phenyltin trichloride and diphenyltin dichloride, ter- and poly-phenyls are also obtained. In some cases tin(IV) chloride or elemental tin are obtained. Pathways that account for all observed products are presented.     

Schwefel-stickstoff-verbindungen VII. Darstellung und reaktionen einiger perfluoraromatischer schwefel-stickstoff-verbindungen

Some reactions of the derivatives of pentafluorobenzenesulfenic, -sulfinic, and -sulfonic acid are described. By the reaction with thionyl chloride N-sulfinylpentafluorobenzenesulfenamide and -sulfonamide were prepared. N-sulfinylpentafluorobenzenesulfenamide was also prepared by the reaction of pentafluorobenzenesulfenyl chloride with N-sulfinyltrimethylsilylamine. Furthermore the reaction of bis(pentafluorophenylthio)amine with thionyl chloride and the reactions of pentafluorobenzenesulfenamide with sulfur dichloride and sulfur tetrafluoride were investigated.     

Spectrophotometric evaluation of interferences in three iron reactions for the determination of serum total cholesterol

A spectrophotometric and chemical evaluation of reported interferences for three iron reactions for the determinations of serum cholesterol has been presented. It has been shown that all three reactions are affected by various interfering substances, such as 2-thiouracil, nitrate, azide, bromide, diethylstilbesterol, and steroids. Spectral differences between the reactions are probably due to solvent and anion effects.The incorporation of uranyl acetate as a precipitating agent into the ferric acetate-uranyl acetate procedure did not make the results obtained comparable with the Abell-type extract of a very icteric serum. Incorporation of ferrous sulfate does not noticeably affect the intensity or stability of color development with standards.As proposed, the ferric acetate-uranyl acetate procedure for the determination of cholesterol represents a modified iron reagent, but the reaction mechanism and the procedure described for it is neither new nor direct. The use of the ferric acetate reagent for serum cholesterol as opposed to ferric chloride, ferric ammonium chloride, or ferric perchlorate appears to have no real advantages as a color reaction. In fact the reaction is less sensitive while reagent preparation is more tedious, time consuming, and expensive than the ferric chloride procedure. Although no quantitative studies were performed, the only effects that chloride had on the reactions were in the region of 400 nm, a wavelength sufficiently far enough away from the 560-nm peak that it did not affect determinations. The concept that the ferric acetate-uranyl acetate reagent contains only acetate and sulfate anions is nullified as soon as one adds serum to the reagents.