Synthesis of aromatic polyesters and polyamides by alternating copolymerizations of 1,4-dicarbonyl-1,4-dihydronaphthalene with bezoquinones and benzoquinone diimines

1,4-Dicarbonyl-1,4-dihydronaphthalene ( 1 ) was synthesized by the dehydrochlorination reaction of 1,4-dihydronaphthalene-1,4-dicarbonyl chloride with triethylamine and obtained as its very dilute solution, but it easily polymerized in the concentration as high as 0.1 mol/L to give its polymer. 1 generated in situ by the dehydrochlorination reaction of 1,4-dihydronaphthalene-1,4-dicarbonyl chloride in a deoxygenated toluene polymerized alternatingly with benzoquinones such as 2-dodecylthio-p-benzoquinone, 2,5-di(tert-butyl)-p-benzoquinone, p-benzoquinone, and 2,3-dichloro-5,6-dicyano-p-benzoquinone, and with benzoquinone diimines such as N,N′-diethoxycarbonyl-p-benzoquinone diimine, N,N′-dibenzoyl-p-benzoquinone diimine, and N,N′-diphenyl-p-benzoquinone diimine to give aromatic polyesters and polyamides, respectively. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1929–1936, 1998     

Quinone copolymerization. I. Reactions of p-chloranil,p-benzoquinone,and 2,5-dimethyl-p-benzoquinone with vinyl monomers under free-radical initiation

The free-radical copolymerization reactions of p-chloranil, p-benzoquinone, and 2,5-di-methyl-p-benzoquinone with vinyl monomers were studied. Reactions of p-chloranil with styrene yielded copolymers of approximately 1:1 composition under a variety of reaction conditions. A copolymer containing a block of 1:1 of styrene:p-chloranil and a block of polystyrene was prepared. Several styrene-like monomers copolymerized with p-chloranil to yield copolymrs possessing considerable amounts of incorporated quinone. p-Benzoquinone copolymerized with 1,3-butadiene and 2-vinyl-pyridine to yield copolymers of significant molecular weights. Reactions of 2,5-dimethyl-p-benzoquinone with vinyl monomers did not yield any isolable polymeric products.     

Reaction of chlorine dioxide with phenol

The kinetics of phenol oxidation with chlorine dioxide in different solvents (2-methylpropan-1-ol, ethanol, 1,4-dioxane, acetone, acetonitrile, ethyl acetate, dichloromethane, heptane, tetrachloromethane, water) was studied by spectrophotometry. In all solvents indicated, the reaction rate is described by an equation of the second order w = k[PhOH]·[ClO₂]. The rate constants were measured (at 10—60 °C), and the activation parameters of oxidation were determined. The reaction rate constant depends on the solvent nature. The oxidation products are a mixture of p-benzoquinone, 2-chloro-p-benzoquinone, and diphenoquinone.     

Poly[amino-p-(hydroquinone or benzoquinone)]amides and poly(p-benzoquinono)diimidazoles of aliphatic dicarboxylic acids. V.

Poly(amino-p-hydroquinone)amides prepared from 2,3,5,6-tetraamino-p-hydroquinone and adipic, suberic, or sebacic acid dichloride were converted by mild oxidation to the corresponding poly(amino-p-benzoquinone)amides. The latter, prepared also directly from 2,3,5,6-tetraamino-p-benzoquinone, were converted by thermal cyclodehydration to the corresponding thermally stable poly(p-benzoquinono)diimidazoles. The prepared new redox polymers were characterized by elemental analysis, UV and IR spectral study, inherent viscosity, solubility, and thermal analysis (DSC, TGA).     

Reactions of poly(methyl methacrylate) radicals with some <Emphasis Type="Italic">p</Emphasis>-quinones in the presence of tri-<Emphasis Type="Italic">n</Emphasis>-butylboron in methyl methacrylate polymerization

The polymerization of methyl methacrylate initiated by dicyclohexyl peroxydicarbonate at 30 °C was studied in the presence of tri-n-butylboron and a series of quinones, namely, p-benzoquinone, chloranil, and 2,5-di-tert-butyl-p-benzoquinone, whose concentration changed from 0.25 to 2.00 mol.%. The initial polymerization rate and molecular weight of poly(methyl methacrylate) depend on the structure and concentration of quinone. The growth radicals react with p-benzoquinone and chloranil predominantly at the C=C bond, while they react at the C=O bond of 2,5-di-tert-butyl-p-benzoquinone. The terminal stable oxygen-centered radicals that formed react with alkylborane, terminating reaction chains and generating alkyl radicals into the bulk. The latter are involved in chain initiation.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2114–2119, October, 2004.     

Electron transfer and paramagnetic products of reactions of haloquinones with aliphatic amines

The reactions of chloranil (Cl₄Q) and bromanil (Br₄Q) with aliphatic amines in a DMF : H₂O (5 : 1, vol/vol) mixture were studied. The radical anions of 2,5-didimethylamino-3,6-chloro-p-benzoquinone and 2,5-didimethylamino-3,6-bromo-p-benzoquinone were identified by ESR spectra. The reaction rate constant of the replacement of two chlorine atoms by the amino groups in the radical anion of Cl₄Q at 288 K was estimated.     

ORGANOPHOSPHORUS COMPOUNDS,XXVIII. THE REACTION OF TRIPHENYLPHOSPHINE SULFIDE WITH TETRACHLOROBENZOQUINONES

Abstract

The reaction of triphenylphosphine sulfide with tetrachloro-o-benzoquinone gives a complex of the corresponding hydroquinone and triphenylphosphine oxide. Elemental sulfur is the other product. The tetrachloro-p benzoquinone does not react to any noticeable extent under similar conditions. Several mechanisms are proposed to explain the results.     

Stereoselective Synthesis of Tricyclo[6.2.2.02,7]dodecane-3,6,9,10-tetrol via Selective Reduction of α,β-Unsaturated 1,4-DIKetone

Stereoselective synthesis of tricyclo[6.2.2.0^2,7]dodecane-3,6,9,10-tetrol was developed starting from p-benzoquinone. The endo selective Diels–Alder cycloaddition of p-benzoquinone and 1,3-cyclohexadiene afforded the corresponding bicyclic diketone. The synthesis of the title compound was based on the cycloadduct by selective reduction with NaBH₄, acetylation with AcCl, and hydroxylation with OsO₄-NMO.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.]     

2-(N-Alkyl-p-hydroxyanilino)-1,4-benzochinone ausp-Benzochinonen und primären aliphatischen Aminen

In acetic (aqueous or chloroform) solutionp-benzoquinones yield with primary aliphatic amines mainly 2-(N-alkyl-p-hydroxy-anilino)-1,4-benzoquinones besides the 2-alkylamino- and 2,5-bis(alkylamino)-quinones. The methyl-, ethyl-,n-propyl-,n-butylhomologues ofp-benzoquinone and the isomer methylderivatives of toluquinone are described. Their structure were established by spectroscopic (UV/VIS, IR, NMR) methods and by synthesis of the methylderivative3 a fromp-benzoquinone andp-hydroxy-N-methylaniline. The influence of other acids on the reaction was studied.

Herrn Prof. Dr.G. Zigeuner, Universität Graz, mit den besten Wünschen zum 60. Geburtstag gewidmet.     

Photolysis of <Emphasis Type="Italic">p</Emphasis>-benzoquinone and <Emphasis Type="Italic">p</Emphasis>-chloranil in aqueous sodium sulfite solution

Photosubstitution of the sulfo group for hydrogen (chlorine in chloranil) is observed under irradiation of sulfonated derivatives of hydroquinone formed upon dissolving of p-benzoquinone and p-chloranil in aqueous solutions of sodium sulfite. The quantum yield of the photochemical reaction is 0.18 ± 0.02 for p-benzoquinone. The rate constant of the thermal reaction of substitution is 5.5 × 10⁻⁴ l mol⁻¹ s⁻¹. The substitution reaction is sensitized by eosin upon irradiation with visible light. During the course of irradiation of sulfohydroquinones, the formation of a product with an absorption maximum at 235 nm was found. The product decays with a rate constant of 0.005 s⁻¹.     

Reaction of o-aminophenol and p-benzoquinone in acetic acid

The reaction of o-aminophenol and p-benzoquinone in acetic acid yields phenoxazinones 1, 5 and 6 , phenoxazine 7 , triphenodioxazine 2 , ditriphenodioxazine 3 and the phenoxazinonyltriphenodioxazine 4 .     

Experiments on the total synthesis of Lysolipin I. Part III. Preparation and transformations of substituted 1,2,3,4-Tetrahydrodibenzofuran-1-ones

1,2,3,4-Tetrahydrodibenzofuran-1-ones were obtained by Michael addition of 1,3-cyclohexadione ( 2 ) to o-benzoquinone ( 3 ) and to p-benzoquinones 8 and 11 (Scheme 2). In addition to the expected 7,8-disubstituted adduct 14 , the ZnCl₂-catalyzed reaction of dione 2 with methoxy-p-benzoquinone ( 11 ) afforded a small amount of the 6,8-disubstituted regio-isomer 13 (Scheme 2). The projected cleavage of these dibenzofuranones to 3-methoxy-2-phenyl-2-cyclohexenone 22 could be effected by treatment with NaOH followed by methylation (Scheme 3). Attempted acetalization of such dibenzofuranones resulted in a retro-Claisen-type cleavage, giving the benzofuryl-butyrate 16 . Other transformations include reduction of the ketone, of the C(4a)=C(9b) bond, and alkylation with Li-ethoxyacetylide (Scheme 3). Oxidation of 8-hydroxy-7-mehoxydibenzofuran derivatives led to o-quinones instead of the desired ring cleavage to p-quinones (Scheme 4).     

Investigation of cationic copolymerization of styrene with p-benzoquinone

The kinetics of copolymerization of styrene with p-benzoquinone in the presence of BF₃OEt₂ is investigated. The rate constants and activation energy of the copolymerization process are determined. The reaction orders for monomer and catalyst are estimated. It is found that the rate of styrene and quinone copolymerization increase and the induction period decreases owing to addition of the latter. It is shown that the copolymerization rate achieves its maximum at an equimolal ratio of monomers. This phenomenon is explained by formation of active molecular complex between styrene and p-benzoquinone. On the basis of obtained data the course of copolymerization is interpreted and the cationic mechanism of copolymerization process is proposed.     

Photo-induced interfacial electron transfer from CdSe quantum dots to surface-bound <Emphasis Type="Italic">p</Emphasis>-benzoquinone and anthraquinone

Here we report transient spectral red-shift and transient absorption enhancement of p-benzoquinone radical in the presence of CdSe quantum dots after 355 nm pulse laser excitation. The spectral shift was caused by surface-bound p-benzoquinone molecules while the transient absorption increase was due to interfacial electron transfer from CdSe quantum dots to p-benzoquinone molecules. In contrast, spectral shift and absorption increase were much less significant for anthraquinone in the presence of CdSe quantum dots due to their weak adsorption abilities.     

Electrochemical synthesis of new organic compounds based on the oxidation of 1,4-dihydroxybenzene derivatives in the presence of primary and secondary amines

An efficient method for the synthesis of 2-benzyl(4-hydroxyphenyl)amino)-6-(benzylamino)-p-benzoquinone derivatives and 2,5-bis-benzyl(methyl)amino)-p-benzoquinone based on the Michael type reaction is described. The electrochemically generated p-benzoquinone reacted with benzylamine derivatives (primary amines) and N-methylbenzylamine (a secondary amine), respectively, to produce the final products. In this work, some new symmetric and asymmetric p-benzoquinone derivatives are synthesized using green solvents with high yields.     

Ladder polyphenoxazines

Two ladder polyphenoxazines have been prepared by the polymerization of 4,6-diaminoresorcinol dihydrochloride (I) with 2,5-dihydroxy-p-benzoquinone (III), or 2,5-diacetoxy-p-benzoquinone (II) and with 2,5-dihydroxy-3,6-dichloro-p-benzoquinone (IV) in a hexamethylphosphoramide (HMP) solvent. When tetrahydrofuran (THF) was the polymerization solvent, the reaction of I with II or IV produced a linear poly-Shiff's base which could be converted to the ladder polymer by heating in HMP. The thermal stability of the ladder polyphenoxazines was surprisingly poor; a slow decomposition started at ca. 275°C. under nitrogen.     

SYNTHESIS OF DIASTEREOMERIC ETHYL 1-BENZOYL-6-(BROMOMETHYL)-2,2,2,4-TETRAPHENYL-3,7-DIOXA-2λ5-PHOSPHABICYCLO- [3.2.0]HEPT-4-ENE-6-CARBOXYLATE

Stable diastereomeric ethyl 1-benzoyl-6-(bromomethyl)-2,2,2,4-tetra- phenyl-3,7-dioxa-2λ ⁵ -phosphabicyclo[3.2.0]hept-4-ene-6-carboxylate was obtained in 98% yield from the reaction between dibenzoylacetylene as electron-deficient acetylenic compound, and ethyl 3-bromopyruvate in the presence of triphenylphosphine in dry ether.     

Comparison of preparation methods of N-arylsulfinyl-1,4-benzoquinone monoimines

Advantages and shortcomings were discussed of three procedures for preparation N-arylsulfinyl-1,4-benzoquinone imines: the reaction of arenesulfenyl chlorides with 1,4-benzoquinone oximes, the oxidation of N-arylthio-1,4-benzoquinone imines, and the reaction of arylsulfinyl chlorides with p-aminophenols followed by oxidation. A series of new N-arylsulfinyl-1,4-benzoquinone imines was obtained.     

Thermal reactions of N,N′ bis(p-nitrophenyl)sulfamide and p-benzoquinone dioxime–acid mixtures

N,N′ Bis(p-nitrophenyl)sulfamide and p-benzoquinone dioxime–acid mixtures were found to undergo an abrupt reaction when heated to give a black polymeric material. These polymeric materials exhibited thermal stability (TGA in N₂) up to 500°C and were insoluble in all solvents including hot concentrated sulfuric acid. From analytical data, structural formulae have been assigned to the polymeric materials that are logically derivable from the starting materials.     

Ionen-Cyclotron-Resonanz-Messungen von Ion/Molekül-Reaktionen bei Chinonen

At a pressure of 10^?6 Torr the ion cyclotron resonance spectra of p-benzoquinone, methyl-p-benzoquinone, tetramethyl-p-benzoquinone and tetrafluoro-p-benzoquinone are identical to the normal mass spectra. Above 10^?5 Torr the spectra show a variety of signals for product ions. From double resonance measurements it was shown that all the product ions are formed by addition of the molecular ion or of a fragment ion to a neutral quinone molecule. In most cases the addition is accompanied by the elimination of carbon monoxide.