Elimination Of Aniline Research Articles

Synthesis of γ‐ and β‐Carbolines via Diphenyl Phosphate‐Mediated Condensation of 3/2‐Carbonyl‐2/3‐Vinylindoles with Phenyl Hydrazine Followed by Electrocyclization

AbstractA facile synthesis of 3‐alkyl‐2‐aryl substituted γ‐carboline derivatives is reported involving diphenyl phosphate catalyzed condensation of 3‐(acetyl/propionyl)‐2‐(nitroaryl)vinyl‐1‐phenylsulfonylindoles with phenyl hydrazine followed by concurrent electrocyclization and aromatization through elimination of aniline. This strategy could be successfully explored with 1‐phenylsulfonylindole‐3/2‐carboxaldehydes containing vinyl unit at 2/3‐position to afford the respective γ‐and β‐carboline derivatives. The domino reaction of easily accessible 2/3‐carbonyl indoles containing a vinyl unit at the adjacent positions with phenyl hydrazine as an amine source afforded a wide variety of carboline derivatives in good to acceptable yields. The synthetic utility of a representative γ‐carboline could be demonstrated via transformation into the corresponding indolo[a]carboline framework.

Design and preparation of highly crystalline K-intercalated W@PCN: an efficient material for aniline elimination

Design and preparation of highly crystalline K-intercalated W@PCN: an efficient material for aniline elimination

Remedial Technologies for Aniline and Aniline Derivatives Elimination from Wastewater.

Background.Aniline and its derivatives are widely used as intermediate chemicals in the pharmaceutical and dye industries and are present in their wastewaters. These chemicals are of concern due to their potential detrimental effects on public health and aquatic species in the environment.Objectives.Various available remedial technologies presented in the literature were investigated to determine the most suitable technology for the elimination of aniline and aniline derivatives from waste streams.Methods.The related literature was collected electronically from ScienceDirect, Google Scholar, the International Agency for Research on Cancer (IARC), ResearchGate and Wiley Online Library for systematic review. The search terms included ‘aniline’, ‘aniline degradation’, ‘advanced oxidation processes (AOPs)’, ‘aniline derivatives’ and ‘Fenton’s reagent'.Discussion.Aniline and its derivatives are a serious issue in the effluents of dye and pharmaceutical industries, but a number of efficient treatment methods using biological, physical and AOPs have been presented in the literature.Conclusions.Comparison of the available technologies showed that AOPs were the most cost effective and efficient technologies for eliminating aniline and its derivatives from wastewater.Competing interests.The authors declare no competing financial interests.

Unclicking of thioureas: Base catalyzed elimination of anilines and isothiocyanates from thioureas

Bisaromatic thioureas are widely used in e.g. asymmetric organocatalysis and considered to be robust compounds. Herein we show, in strong contrast to common notion, that thioureas dissociate to amines and isothiocyanates in a base catalyzed reaction under mild conditions. This ‘unclicking’ process can occur in the presence of weak organic bases even at moderate temperatures. The influence of the substituents at the aromatic rings of the thiourea on the regioselectivity of this unclicking process is also shown.

Degradation of aniline by electrochemical activation of peroxydisulfate at MWCNT cathode: The proofed concept of nonradical oxidation process

Enhanced elimination of aniline in aqueous solution was achieved by coupling electrosorption of aniline and electrochemical activation of peroxydisulfate (PDS) at multi-walled carbon nanotube (MWCNT) cathode, in which a synergistic effect occurred. It was found that PDS could be effectively activated under a small voltage at MWCNT cathode owing to the specific pore structures of MWCNTs. A nonradical oxidation pathway instead of radical-based oxidation was proposed from the cathodic activation of PDS, wherein PDS molecules with a modified electronic structure was suggested to be the principal reactive species. Meanwhile, the influences of various operation parameters such as electrode potential, PDS concentration, presence of chloride ions on the elimination efficiency, and the stability of MWCNT electrode were also attempted. Therefore, the electrochemical activation of PDS by MWCNT cathode is a promising energy-saving method for the treatment of organic pollutants in wastewater.

Electrochemical oxidation of aniline by a novel Ti/TiOxHy/Sb-SnO2 electrode

Electrochemical oxidation of aniline in aqueous solution was investigated over a novel Ti/TiOxHy/Sb-SnO2 electrode prepared by the electrodeposition method. Scanning electron microscopy, X-ray diffraction, and electrochemical measurements were used to characterize its morphology, crystal structure, and electrochemical properties. Removal of aniline by the Ti/TiOxHy/Sb-SnO2 electrode was investigated by ultraviolet-Visible spectroscopy and chemical oxygen demand (COD) analysis under different conditions, including current densities, initial concentrations of aniline, pH values, concentrations of chloride ions, and types of reactor. It was found that a higher current density, a lower initial concentration of aniline, an acidic solution, the presence of chloride ions (0.2 wt% NaCl), and a three-dimensional (3D) reactor promoted the removal efficiency of aniline. Electrochemical degradation of aniline followed pseudo-first-order kinetics. The aniline (200 mL of 100 mg L−1) and COD removal efficiencies reached 100% and 73.5%, respectively, at a current density of 20 mA cm−2, pH of 7.0, and supporting electrolyte of 0.5 wt% Na2SO4 after 2 h electrolysis in a 3D reactor. These results show that aniline can be significantly removed on the Ti/TiOxHy/Sb-SnO2 electrode, which provides an efficient way for elimination of aniline from aqueous solution.

Microwave-Synthesized Barium-Impregnated Siliceous Zeolitic Material Derived from Bagasse Fly Ash for Uptake of Aniline

Aniline has been present in wastewater discharged from chemical manufacturing industries which has great impact on human health and environment. Bagasse fly ash (BFA) is a sugar industry waste and synthesized into zeolitic materials used for elimination of aniline from aqueous solution. The microwave-assisted technique employed for transformation of BFA into zeolitic material which was EMZBFA-Ba (electrolyte-treated microwave-irradiated zeolite of bagasse fly ash-barium). It was further modified with Si/Al ratio 30 (EMZBFA-30-Ba) to enhance its hydrophobicity for better sorption of aniline. The synthesized zeolites were characterized by X-ray fluorescence analysis, powdered X-ray diffraction, Fourier transformed infrared spectroscopy, Barrett–Joyner–Halenda, Brunauer–Emmett–Teller and scanning electron microscopy. The characterized materials result confirmed the existence of major minerals such as harmotome, analcime and barium chloroaluminosilicate zeolitic materials. Barium was incorporated into zeolite for structure directing and crystallinity improvement which also enhanced sorption of aniline. The efficacy of removal of aniline was tested at optimum sorption conditions which do have average sorption capacity of 39.06, 45.02 and 48.59 mg/g for BFA, EMZBFA-Ba and EMZBFA-30-Ba, respectively. Langmuir and Freundlich model fitted for sorption process, while the kinetic studies showed that pseudo-second-order rate, intraparticle diffusion and surface sorption were suitable for sorption of aniline. From thermodynamic study, the major interactions of sorbate and sorbent were hydrogen bonding, dipole forces and chemical bond because these strong forces of interaction sorbents may not be highly regenerated.

A Domino Reaction of 3-Methyl-1-[6-Methyl-2-(Methylsulfanyl)Pyrimidin-4-yl]-4-[(Phenyl-Imino)Methyl]-1H-Pyrazol-5-ol with Hetero-Cyclic ch Acids

The reaction of 3-methyl-1-[6-methyl-2-(methylsulfanyl)pyrimidin-4-yl]-4-[(phenylimino)methyl]-1H-pyrazol- 5-ol with heterocyclic CH acids is accompanied by a formal cleavage of the substrate and the formation of substituted 1-(pyrimidin-4-yl)pyrazole and aniline. The possibility of isolation of the azomethine (aminomethylеne) derivative of CH acids formed in the process depends on the electrophilicity of its α-carbon atom. In the case of increased electrophilicity, this compound reacts in situ with CH acid to form methylеne bis-СН acids with elimination of aniline.

CYP2E1 hydroxylation of aniline involves negative cooperativity

CYP2E1 plays a role in the metabolic activation and elimination of aniline, yet there are conflicting reports on its mechanism of action, and hence relevance, in aniline metabolism. Based on our work with similar compounds, we hypothesized that aniline binds two CYP2E1 sites during metabolism resulting in cooperative reaction kinetics and tested this hypothesis through rigorous in vitro studies. The kinetic profile for recombinant CYP2E1 demonstrated significant negative cooperativity based on a fit of data to the Hill equation (n=0.56). Mechanistically, the data were best explained through a two-binding site cooperative model in which aniline binds with high affinity (Ks=30μM) followed by a second weaker binding event (Kss=1100uM) resulting in a threefold increase in the oxidation rate. Binding sites for aniline were confirmed by inhibition studies with 4-methylpyrazole. Inhibitor phenotyping experiments with human liver microsomes validated the central role for CYP2E1 in aniline hydroxylation and indicated minor roles for CYP2A6 and CYP2C9. Importantly, inhibition of minor metabolic pathways resulted in a kinetic profile for microsomal CYP2E1 that replicated the preferred mechanism and parameters observed with the recombinant enzyme. Scaled modeling of in vitro CYP2E1 metabolism of aniline to in vivo clearance, especially at low aniline levels, led to significant deviations from the traditional model based on non-cooperative, Michaelis–Menten kinetics. These findings provide a critical mechanistic perspective on the potential importance of CYP2E1 in the metabolic activation and elimination of aniline as well as the first experimental evidence of a negatively cooperative metabolic reaction catalyzed by CYP2E1.

ChemInform Abstract: Novel Sulfamic Acid‐Promoted Synthesis of 3‐Alkylidene Indolone Derivatives in the Presence of Aniline via One‐Pot Multicomponent Reaction.

Abstract A sulfamic acid–catalyzed synthesis of 3-alkylidene indolone derivatives by addition of dialkyl acetylenedicarboxylate to isatin derivatives in the presence of aniline is reported. The reaction sequence consists of an initial Michael addition of aniline to dialkyl acetylenedicarboxylate, followed by aldol-like reaction with isatin, and then elimination of aniline to afford the product.

Novel Sulfamic Acid–Promoted Synthesis of 3-Alkylidene Indolone Derivatives in the Presence of Aniline via One-Pot Multicomponent Reaction

A sulfamic acid–catalyzed synthesis of 3-alkylidene indolone derivatives by addition of dialkyl acetylenedicarboxylate to isatin derivatives in the presence of aniline is reported. The reaction sequence consists of an initial Michael addition of aniline to dialkyl acetylenedicarboxylate, followed by aldol-like reaction with isatin, and then elimination of aniline to afford the product.

Thermal and FTIR spectral studies of N,N′-diphenylguanidine

Thermal decomposition of N,N′-diphenylguanidine (DPG) was investigated by simultaneous TG/DSC-FTIR techniques under nonisothermal conditions. Online FTIR measurements illustrate that aniline is a major product of DPG decomposition. The observation that the activation energy depends on the extent of conversion indicates that the DPG decomposition kinetics features multiple processes. The initial elimination of aniline from DPG involves two pathways because of the isomerization of DPG. Mass spectrometry and thin film chromatography suggest that there are two major intermediate products with the major one of C21N3H17. The most probable kinetic model deduced through multivariate nonlinear regression method agrees well with the experimental data with a correlation coefficient of 0.9998. The temperature-independent function of conversion f(α), activation energy E and the pre-exponential factor A of DPG decomposition was also established through model-fitting method in this research.

Flash vacuum pyrolysis of N-phenylbenzamide oxime and related compounds

Flash vacuum pyrolysis (FVP) of the benzamide oxime 1 at 650 °C leads to the imino-oxadiazole 10 as the major product. It is probably formed by intermolecular cycloaddition of benzonitrile oxide 11 and the diphenylcarbodiimide 12, an unexpected process to take place under FVP conditions. Intermediates 11 and 12 are themselves obtained by competitive dehydration and elimination of aniline from 1. Mixed products were obtained from FVP of the C- and N- p-tolyl analogues of 1 ( 5 and 6, respectively) probably owing to equilibration of the carbodiimide intermediate.

Synthesis of Cp−Re Complexes via Olefinic C−H Activation and Successive Formation of Cyclopentadienes

Treatment of an alpha,beta-unsaturated ketimine with an alpha,beta-unsaturated carbonyl compound in the presence of a rhenium complex, Re2(CO)10, gave a cyclopentadienyl-rhenium complex. This reaction proceeds via rhenium-catalyzed C-H bond activation of an olefinic C-H bond, insertion of an alpha,beta-unsaturated carbonyl compound into a Re-C bond of the alkenylrhenium intermediate, intramolecular nucleophilic cyclization, reductive elimination, elimination of aniline to give a cyclopentadiene derivative, followed by the formation of a cyclopentadienyl-rhenium complex from the cyclopentadiene derivative and the rhenium complex.

New Phosph(V)azane Ligand as a Bidentate Donor in the Synthesis of One Novel Organometallic Tin(IV) Compound

The new ligand {[(C6H5NH)P(O)H](NC6H5)[(C6H5NH)P(O)H]} ( 2 ) was synthesized by heating bis(anilino)phosphine oxide (C6H5NH)2P(O)H ( 1 ) at 110°C and elimination of aniline. The treatment of 2 with SnBu2 Cl2 in the presence of triethylamine (TEA) in dry THF yielded the novel compound Bu n 2Sn{[Et3NH(NPh)P(O)H](NPh)p(O)H]}2 ( 3 ) in which the phosphazane ligand acts as a bidentate ligand. The products have been characterized by means of elemental analysis, IR, MS, and multinuclear NMR ( 1H, 13C, 31P, and 119Sn) spectroscopy. The spectroscopic data are consistent with the bounding of the phosph(V)azane ligand through both oxygen and phosphorus atoms to Sn(IV) center in the final compound 3 . TEA is used as a base in order to deprotonate the phosphazane ligand and is separated as Et3 NH + Cl − , whereas HTEA + exists in the title product 3 and is acting as a charge balancing and H-bond structure directing agent.

Rhenium-catalyzed synthesis of naphthalene derivatives via insertion of aldehydes into a C–H bond

A rhenium complex, [ReBr(CO) 3(THF)] 2, catalyzed reactions of aromatic ketimines and aldehydes with dienophiles, followed by dehydration, to give naphthalene derivatives in good to excellent yields. This reaction proceeds via C–H bond activation, insertion of an aldehyde, intramolecular nucleophilic cyclization, reductive elimination, elimination of aniline and Diels–Alder reaction. After dehydration, naphthalene derivatives were formed.

Activity of free peroxidases, hematin, magnetite-supported peroxidases and magnetite-supported hematin in the aniline elimination from water-UV–vis analysis

This manuscript presents the UV–vis study of the aniline elimination by polymerization using peroxidases from different sources and hematin, free and supported. The use of magnetite-supported hematin has potential in the implementation of aniline elimination by polymerization in acidic media at pH 4. The temperature must be selected between 45 and 65 °C. Crude preparations of Pleurotus sajor caju (PSC) are an alternative to purified Horseradish peroxidase (HRP) as the catalyst of the reaction. Pernigraniline is the main species found in the reaction media after aniline elimination procedure. Supported oxidoreductases are active biocatalysts and conversion of aniline in the 30–90% range can be obtained, depending on the catalyst. The UV–vis spectra show bands corresponding to base and protoned (blue and purple-deep red) pernigraniline, a contribution of quinoid species at 480 nm and a minor contribution of base blue emeraldine and another oxidation intermediate states between pernigraniline and emeraldine. At selected conditions, the recovered solid showed greenish/reddish coloration. The goal is the precipitation of the aniline as polyaniline. Supported biocatalysts were less active than free enzymes.

Synthesis of Polysubstituted Quinolines from the Acetates of Baylis—Hillman Adducts: Aza‐Claisen Rearrangement as the Key Step.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis of Polysubstituted Quinolines from the Acetates of Baylis-Hillman Adducts: Aza-Claisen Rearrangement as the Key Step

Recently, we have reported a variety of chemical transformations of the Baylis-Hillman adducts into useful heterocyclic compounds. Very recently, we published the synthesis of 3-benzylquinolin-2-ols from the Baylis-Hillman adducts of ethyl acrylate bearing aniline moiety at the secondary position. 3-Benzylquinolin-2-ols could be formed via the sequential aza-Claisen rearrangement of the adduct in PPA, amide bond formation, and the following isomerization with the aid of DBU as shown in Scheme 1. In this paper we would like to report our results on the synthesis of polysubstituted quinolines from the BaylisHillman adducts of alkyl vinyl ketones. As exemplified in Scheme 2, the required starting materials 2 were synthesized from the acetates of the Baylis-Hillman adducts of methyl vinyl ketone and ethyl vinyl ketone via the corresponding DABCO salts according to the reported procedure. In the reaction, however, cinnamyl amine derivatives 3 were isolated in variable yields (6-37%) depending upon the nature of anilines (Table 1) as side products. The formation of primary adducts 3 from 2 under the reaction conditions can be explained by sequential addition and elimination of aniline, presumably due to the higher electrophilicity of the β-carbon (marked with asterisk) of 2 than the cases of ethyl acrylate (Scheme 1). As can be seen easily in the ratios of 2 and 3 (Table 1), the amounts of primary products 3 were gradually increased according to the increase of the nucleophilicity of anilines. With the compound 2a in hand we examined the reaction in PPA at various reaction temperatures. Mixed solvent system of PPA and 1,2-dichloroethane was used in order to

Distinct thermodynamics for the formation and cleavage of N-H bonds in aniline and ammonia. Directly-observed reductive elimination of ammonia from an isolated amido hydride complex.

The reactions of aryl and alkylamines with the (PCP)Ir fragment (PCP = 1,3-di-tert-butylphosphinobenzene) were studied to determine the reactivities and stabilities of amine and amido hydride complexes relative to C-H activation products. Reaction of aniline with the (PCP)Ir unit generated from (PCP)IrH2 and norbornene resulted in the N-H oxidative addition product (PhNH)(H)Ir(PCP) (1a). In contrast, reaction of this fragment with ammonia gave the ammonia complex (NH3)Ir(PCP) (2). The amido hydride complex that would be formed by oxidative addition of ammonia, (PCP)Ir(NH2)(H) (1b), was generated independently by deprotonation of the ammonia complex (NH3)Ir(H)(Cl)(PCP) (3) with KN(SiMe3)2 at low temperature. This amido hydride complex underwent reductive elimination at room temperature to form the ammonia complex 2. Addition of CO to anilide complex 1a gave (PCP)Ir(PhNH)(H)(CO) (4a). Addition of CNtBu to terminal amido complex 1b formed (PCP)Ir(NH2)(H)(CNtBu) (4b), the first structurally characterized iridium amido hydride. Complexes 4a and 4b underwent reductive elimination of aniline and ammonia; parent amido complex 4b reacted faster than anilide 4a. These observations suggest distinct thermodynamics for the formation and cleavage of N-H bonds in aniline and ammonia. Complexes 1a, 2, 4a, and 4b were characterized by single-crystal X-ray diffraction methods.