Novel synthesis of polymeric phase transfer catalysts containing N,N-dialkylacrylamide unit and their catalytic activity

Soluble polymeric phase transfer catalysts (PTCs) containing benzyltributylphosphonium chloride moieties and polar N,N-dialkyl-acrylamide with long alkyl groups such as N,N-dipropylacrylamide, N,N-dibutylacrylamide, N,N-dihexylacrylamide, and N,N-dioctylacrylamide were prepared via two-step reactions from p-chloromethylstyrene and the corresponding N,N-dialkylacrylamide. When the obtained polymers were added, the phase transfer catalyzed reaction of benzylchloride with solid potassium acetate to proceed smoothly. The catalytic activity was strongly affected by the content of phosphonium chloride and the varieties of comonomer unit in the polymeric PTC. The polymeric PTC containing the N,N-dihexylacrylamide unit showed excellent high catalytic activity in a low polar solvent such as the mixed solvent of toluene with 70 vol % n-tridecane. Therefore, the polymer containing lipophilic long chains such as the hexyl group is desirable for polymeric PTC. © 1996 John Wiley & Sons, Inc.     

Flow Injection Analysis of Benzoyl Peroxide Using N,N,N,N-Tetramethyl-p-phenylenediamine (TMPDA) and Surfactants

Abstract

The flow injection analysis of benzoyl peroxide using N,N,N,N-tetramethyl-p-phenylenediamine (TMPDA, also known as Wurster's reagent) and a solvent system including the surfactant sodium dodecyl sulfate (SDS) and cerium(IV) as a catalyst at pH 6.0 at 612 nm was investigated. The method was applied to the analysis of acne cream and flour. The study included a 26-metal-ion search for other possible methods of catalysis and a buffer study of SDS and cetyltrimethyl ammonium bromide (CTAB).     

Application of N,N'-Diiodo-N,N'-1,2-ethandiylbis(p-toluene sulfonamide)as a New Reagent for Synthesis of2-Arylbenzimidazoles and 2-Arylbenzothiazoles under Solvent-free Conditions

N,N′‐Diiodo‐N,N′‐1,2‐ethandiylbis(p‐toluene sulfonamide) (NIBTS) is a good and new reagent for synthesis of 2‐arylbenzimidazoles and 2‐arylbenzothiazoles at room temperature under solvent‐free condition with good to high yield. Absence of solvent, short reaction times, non‐corrosive, operational simplicity and environmentally friendliness are the main advantages of this procedure.     

Heterocyclen aus Bis(alkoxycarbonyl)keten-ethylen-acetalen ( = Dialkyl-2-(1,3-dioxolan-2-yliden)propan-1,3-dioate). Synthese und Eigenschaften einer neuen Klasse von Pyrazolium-Betainen

Heterocycles Starting from Bis(alkoxycarbonyl)ketene Ethylene Acetals ( = Dialkyl 2-(1,3-Dioxolan-2-ylidene)propane-1,3-dioate). Synthesis and Properties of a New Class of Pyrazolium Betaines The readily available bis(alkoxycarbonyl)ketene ethylene acetals 1 react with bifunctional nucleophiles to give heterocycles 2–5 (Scheme 1). Their reactions with N,N-dialkylhydrazines lead to the pyrazolium betaines 7a–f (Scheme 4). Cyclic N,N-dialkylhydrazines give spiro compounds 7d–f . The reaction of thioketene acetal 12 and of the derivative 15 of methanetricarboxylic acid with N,N-dimethylhydrazine results in the formation of 3-(methylthio)- and 3-methoxypyrazolium betaine 7g and 7h , respectively (Scheme 4). The chemical reactivity of the synthesized pyrazolium betaines 7 was tested. The structure of the 3-(methylthio) derivative 7g was determined by X-ray analysis.     

High-pressure alkylation of bis(benzylidene)phenylenediamines

The reactions of alkyl chlorides with bisanils (obtained from o-, m-, and p-phenylenediamines) under high pressure (10 kbar) were studied. Depending on the structure of the starting diamines and the solvent nature, hydrolysis of the reaction mixtures gave pure N-monoalkyl- or N,N"-dialkylphenylenediamines in high yields. The effect of the phase transition of the solvent on the direction of alkylation is discussed.     

Preparation and properties of N-phenylated aromatic polyamides from N,N′-diphenyl-p-phenylenediamine and aromatic diacid chlorides

N-Phenylated aromatic polyamides and copolyamides derived from N,N′-diphenyl-p-phenylenediamine, isophthaloyl, and terephthaloyl chloride were prepared by high-temperature solution polycondensation in anisole at 155°C. Factors that influenced the reaction, such as monomer concentration, solvent, temperature, and time, were studied to determine the optimum conditions for the preparation of high molecular weight polymers. Compared with analogous unsubstituted aromatic polyamides, the N-phenylated polymers exhibited better solubility in chlorinated and amide solvents, reduced crystallinity, and lower glass transition temperatures (above 200°C). All polymers except the polyterephthalamide could be solvent-cast, as well as hot-pressed, into transparent flexible films.     

Spectroscopic studies on N,N-dimethylamides—I: Structure-reactivity correlation for rotational barriers from a nuclear magnetic resonance study of p- and m-substituted N,N-dimethylbenzamides

Rotational barriers in 21 p- and m-substituted N,N-dimethylbenzamides in CDCl₃ as solvent have been determined using the intensity ratio method of Woodbrey. These data compare very well with values from the literature¹ obtained with a total line shape analysis. From structure-reactivity correlations evidence has been obtained for a relatively strong resonance interaction between the substituent in the aromatic ring and the partially double amide bond.     

Mild Oxidation of 1,3,5‐Trisubstituted Pyrazolines with N‐Bromo‐sulphonamides

1,3,5‐Trisubstituted pyrazolines to pyrazoles are carried out efficiently in the presence of new reagents N,N,N′, N′‐tetrabromo‐benzene‐1,3‐disulfonylamine [TBBDA] and N,N′‐dibromo‐N,N′‐1,2‐ethanediylbis‐(p‐toluenesulphonamide) [BNBTS] in solvent‐free conditions with catalytic amounts of SiO₂ under microwave irradiation in high yields.     

Synthesis and characterization of N-phenylated aromatic polyureas from N,N′ -dichloroformyl-p-dianilinobenzene and N,N′ -bistrimethylsilyl-diamines

NovelN-phenylated aromatic polyureas having inherent viscosities of 0.13–0.35 dL/g were synthesized by the solution polycondensation of N,N′-dichloroformyl-p-dianilinobenzene with N,N′-bistrimethylsilyl derivatives of bis(4-aminophenyl)ether, piperazine, and p-dianilinobenzene in sulfolane. Except the polyurea containing piperazine unit, the other polyureas were amorphous and readily soluble in a variety of organic solvents such as tetrahydrofuran. The polyurea derived from p-dianilinobenzene, which has no vulnerable hydrogen on the urea linkage, did not melt below 350°C and was stable up to 450°C in air.     

Inhibited Polymerization of N,N,N-Trimethylammonioethyl Methacrylate Methyl Sulfate

The kinetic features of initiation of N,N,N-trimethylammonioethyl methacrylate methyl sulfate polymerization in the presence of manganese(III) bis(acetylacetonate) nitrate and p-nitrosoaniline were studied by the inhibited polymerization method. The kinetic parameters of initiation were calculated, and participation of the monomer in the initiation stage was established.     

Thio Analogs of Pyrimidine Bases: Synthesis And Spectroscopic Study of New Potentially Biologically Active Disulfides of N,O-(N,N- or O,O-)-Di- and N,N,O-Tri-(o-, m-, and p-)bromobenzyl-2-thiouracils

Nine new disulfides of N,O-(N,N- or O,O-)-di- and N,N,O-tri-(o-, m- and p-)bromobenzyl-2-thiouracils have been prepared. The structures of these compounds were confirmed by spectroscopic (FT-IR, UV-Vis, ¹H NMR) and elemental analyses. Estimation of pharmacotherapeutic potential has been made for synthesized compounds on the basis of Prediction of Activity Spectra for Substances (PASS).     

Fluorescence self-quenching of substituted N,α-diphenylnitrones in various solvents

Photophysical and photochemical properties for N,α-diphenylnitrone 1a, α-p-methoxyphenyl-N-phenylnitrone 1b, N-(t-butyl)-α-phenylnitrone 1c, cis-α-cyano-N,α-diphenylnitrone 1d, trans-α-cyano-N,α-diphenylnitrone 1e, α-methoxycarbonyl-N,α-diphenylnitrone 1f and α-ethoxycarbonyl-N,α-diphenylnitrone 1g were investigated. Photolysis studies in polar and protic solvent such as ethanol revealed that the singlet-state formation was preferred in nitrones and this was confirmed by the fluorescence investigations. Absorption and fluorescence spectra indicated considerable shifts with variation in polarity of the solvent.     

The effect of solvents on the 13C NMR chemical shifts of the carbonyl carbon and the rotational barriers of N,N-dimethylbenzamide

The ¹³C solvent induced chemical shifts (SICS) of the carbonyl carbon and the thermodynamic barriers to rotation about the C? N bond of N,N-dimethylbenzamide are linearly related to the solvent parameter, E_T(30). A multi-parametric solvent parameter approach indicates that the SICS are influenced equally by polar effects and hydrogen-bond donor effects. Rotational barriers for N,N-dimethylbenzamide may, in principle, be determined by measurement of the ¹³C chemical shift of the carbonyl carbon in a particular solvent.     

Screening of N,N‐bidentate and N,N,N‐tridentate pyridine‐based ligands in the catalytic allylic oxidation of cyclic olefins

A variety of chiral N,N‐bidentate and N,N,N‐tridentate ligands based on the pyridine framework, namely C2‐symmetric dipyridylmethane and terpyridine, N‐(p‐toluensulfinyl)iminopyridines and two kinds of iminopyridines, has been assessed in the asymmetric copper(I)‐catalysed allylic oxidation of cyclic olefins. Catalytic activity and enantioselectivity were found to be highly dependent upon the framework of the ligands, which afforded cycloalkenyl benzoates in low to moderate yields and enantioselectivities. The best yields (up to 70%) and enantioselectivities (up to 53% enantiomeric excess) were obtained with an iminopyridine based on camphane and quinoline skeletons. Copyright © 2014 John Wiley & Sons, Ltd.     

The Electrochemically Initiated Reaction of Sulfide with N,N‐Diethyl‐p‐phenylenediamine in Dimethylformamide. Part II: Implications for Sensing Strategies

The electrochemically initiated reaction of p‐phenylenediamines with sulfide in aqueous media is well documented. We now report the adaptation of this chemistry into nonaqueous media. This is critically appraised as a means of detecting sulfide. The electrochemically initiated reaction of N,N‐diethyl‐p‐phenylenediamine with sulfide is shown at both macro‐ and platinum microdisk electrodes with quantitative detection of sulfide produced by means of the enhanced currents observed upon its addition. The linear detection range for sulfide is dependent on the concentration of N,N‐diethyl‐p‐phenylenediamine present with a linear range from 28–3290 μM and a limit of detection of 22 μM achievable. This represents a large increase compared to that found previously in aqueous media and offers the prospect of more ready applications in high temperature systems.     

Synthesis of N-substituted bisitaconimide monomers for use as thermosetting polyimide resins

Two monomeric N-substituted bisitaconimides, N,N′-bisitaconimido-p,p′-diphenylmethane and N,N′-bis(itaconimido-p,p′-diphenyl ether), were synthesized from the corresponding diamines. The synthesis was accomplished by reaction of the diamine with itaconic anhydride and cyclocondensation of the resultant bisitaconamic acid. Attempts to use p,p′-diaminodiphenylsulfone as the diamine gave N,N′-biscitraconimido-p,p′-diphenylsulfone and N-citraconimido-N′-itaconimido-p,p′-diphenylsulfone instead of the bisitaconimide. The two bisitaconimides polymerize thermally at 180°C and 225°C, respectively, and yield tough polymers with very high thermal stability.     

Ce(SO4)2‐Mediated Nitration of N,N‐Dialkylanilines with NaNO2 in Water

Ce(SO₄)₂‐mediated nitration of N,N‐dialkylanilines with NaNO₂ using water as the solvent has been achieved in good to excellent yields. The nitrating reaction proceeded smoothly at ambient temperature.     

Contrasting chemical and physical properties of [o- and [p-(N,N-dimethylamino) phenyl]phosphines and phosphonium salts

The rate of alkylation of (2-N,N-dimethylaminophenyl)diphenylphosphine with benzyl bromide in chloroform is faster than that of the corresponding reaction of (4-N,N-dimethylaminophenyl)diphenylphosphine. This result is discussed in terms of a through-space N_2p–P(IV) interaction for the former. The rate of alkaline cleavage of benzyl(4-N,N-dimethylaminophenyl)diphenylphosphonium bromide, which gives toluene, is slower than the rate of alkaline cleavage of benzyl(2-N,N-dimethylaminophenyl)diphenylphosphonium bromide, which gives dimethylaniline. This result is also discussed in terms of the through-space N_2p–P(IV) interaction. The ³¹P NMR spectra of a series of ortho-dimethylamino-substituted triarylphosphines and benzyltriarylphosphonium halides show that the phosphorus atom is more shielded than in the corresponding para-dimethylamino compounds, as anticipated on the basis of an N_2p–P(IV) interaction for the former.     

Stabilization of p-Phenylenebis(N-tert-butylaminoxyl) Relative to p-Benzoquinonediimine N,N′-Dioxide

Steric interactions between methoxy and tert -butyl groups are the reason that 2 only exists as p-phenylenebis(N-tert-butylaminoxyl) B . The p-phenylenebis(N-tert-butylaminoxyl) 1 has the p-quinonediimine N,N′-dioxide structure Q in solution as well as in the crystalline state.     

Synthesis and Structure of N,N-Dimethyldithiocarbamates of Tetraphenylantimony and Tetra-p-tolylantimony

Tetraphenylantimony N,N-dimethyldithiocarbamate (I) and tetra-p-tolylantimony N,N-dimethyldithiocarbamate (II) were synthesized via the reaction of tetraarylantimony chloride Ar₄SbCl (Ar = C₆H₅ or C₆H₄Me-4) with sodium N,N-dimethyldithiocarbamate in water. According to the X-ray diffraction data, the tetraarylantimony N,N-dimethyldithiocarbamate molecules have a distorted octahedral configuration. The Sb–S bond lengths are equal to 2.7158(5) Å, 2.7440(5) Å and 2.761(2) Å, 2.8002(2) Å for I and II, respectively.