Ordinary Organic Solvents Research Articles

Synthesis and Properties of Novel Aromatic Poly(thioether−ketone)s as Sulfur-Containing High-Performance Polymers

Novel aromatic poly(thioether−ketone)s (PTEKs) bearing the 2,6-dimethyl-1,5-naphthylene units were synthesized by the polycondensation of aromatic dihaloketones and aromatic dithiols in the presence of K2CO3. PTEKs with molecular weight (Mn ∼ 65 000, Mw ∼ 350 000) were obtained in quantitative yields. The molecular weights and yields of PTEKs obtained from aromatic dichloroketone and aromatic dithiols were much higher than those of the corresponding poly(ether−ketone)s (PEKMNs) obtained from aromatic dichloroketone and biphenols and were nearly the same as those of PTEKs obtained from aromatic difluoroketone and aromatic dithiols. The effect of reaction conditions on yield and molecular weight of PTEKs was investigated. The PTEKs had high solubility in ordinary organic solvents. Flexible, transparent, and strong films were cast from CHCl3 solution. PTEK-1 and PTEK-2 had high glass transition temperatures (Tg; PTEK-1 245 °C, PTEK-2 215 °C) and 5% weight loss temperatures (Td5; PTEK-1 435 °C, PTEK-2 436 °C).

Ferroelectric liquid crystalline polythiophene derivatives

Chiral liquid crystalline (LC) substituent with fluorine-containing asymmetric moiety was introduced into the 3-position of thiophene ring. Polythiophene derivatives were fusible and soluble in ordinary organic solvents. Phase transition behaviors of the polymers and monomers were examined by differential scanning calorimetry, polarizing optical microscope, and X-ray diffraction. The polymers showed several types of smectic phases in the heating and cooling processes. Besides, one of the polymers exhibited a chiral smectic C phase (Sc*), which is indispensable for ferroelectricity. The ferroelectric behavior was also confirmed by examining the temperature dependence of dielectric constant of the polymer.

Synthesis, characterization and photoreaction of photoreactive side-chain liquid-crystalline copolymers comprising 2-benzoylethoxybiphenyl and 3-methyl-2-butenyloxybiphenyl side groups

Photo-crosslinkable side-chain liquid-crystalline copolymers comprising 2-benzoylethoxybiphenyl and 3-methyl-2-butenyloxybiphenyl groups were synthesized and characterized. Thermal behavior of the copolymers was determined by differential scanning calorimetry and polarized optical microscopy. All synthesized copolymers were liquid-crystalline having nematic and/or smectic phases, and their mesomorphic transition temperatures hardly varied with composition of the copolymers. Photochemically crosslinked copolymer films obtained by UV-irradiation were insoluble in ordinary organic solvents.

Synthesis, characterization and photoreaction of photoreactive side-chain liquid-crystalline copolymers comprising 2-benzoylethoxybiphenyl and 3-methyl-2-butenyloxybiphenyl side groups

Photo-crosslinkable side-chain liquid-crystalline copolymers comprising 2-benzoylethoxybiphenyl and 3-methyl-2-butenyloxybiphenyl groups were synthesized and characterized. Thermal behavior of the copolymers was determined by differential scanning calorimetry and polarized optical microscopy. All synthesized copolymers were liquid-crystalline having nematic and/or smectic phases, and their mesomorphic transition temperatures hardly varied with composition of the copolymers. Photochemically crosslinked copolymer films obtained by UV-irradiation were insoluble in ordinary organic solvents.

Synthesis and properties of poly(arylene-ether-ketone)s containing a dimethylnaphthalene skeleton in the main chain

The synthesis of novel dihaloarenes (1,5-bis(4-halophenyl)-2,6-dimethylnaphthalenes, 1), polycondensation of 1 with biphenols, and properties of the obtained polymers were described. Selectively Friedel-Crafts acylation of 2,6-dimethylnaphthalene with 4-halobenzoyl chlorides in nitrobenzene afforded 1 in high yields. X-Ray single-crystal structural analysis of 1 supported that the dibenzoylation proceeded regioselectively at the 1- and 5-positions and the two methyl groups sterically inhibited the coplanarity of the aromatic planes. The polycondensation of 1a with Bisphenol A in toluene/ N-methyl-2-pyrrolidone (NMP) mixed solvent in the presence of excess potassium carbonate as a condensation reagent was carried out at 180°C for several hours to quantitatively afford the corresponding poly(arylene-ether-ketone) (PEK) 3 with a high molecular weight ( M n −30,000) as a slightly yellow powder. To evaluate the effect of the methyl groups of 3, polycondensation of 2,6-bis(4-fluorobenzoyl)naphthalene 2 with Bisphenol A was carried out for comparison and the corresponding PEK 4 was obtained quantitatively. Whereas 3 was soluble in ordinary organic solvents such as tetrahydrofuran (THF) and chloroform at room temperature, 4 was insoluble in common solvents except for strong acids such as conc. sulfonic acid. 3 showed a high glass-transition temperature (238°C) and a 5% weight loss temperature of 457°C. The polycondensations of 1a with various biphenols such as dihydroxybenzophenone were carried out to examine the properties of the obtained polymers. The obtained PEKs showed high glass transition temperatures and 5% weight loss temperatures as well as good solubilities in ordinary organic solvents at room temperature. Casting of the polymers from THF solution gave transparent, tough, flexible, and amorphous films. 1,5-Bis(4-chlorobenzoyl)-2,6-dimethylnaphthalene 1b similarly underwent a polycondensation reaction with Bisphenol A to give the corresponding polymer quantitatively.

Synthesis of a novel naphthalene‐based poly(arylene ether‐ketone) by polycondensation of 1,5‐bis(4‐fluorobenzoyl)‐2,6‐dimethylnaphthalene with bisphenol a

AbstractSynthesis of 1,5‐bis(4‐fluorobenzoyl)‐2,6‐dimethylnaphthalene (1), polycondensation of 1 with Bisphenol A, and properties of the obtained polymer were studied. Friedel–Crafts acylation of 2,6‐dimethylnaphthalene with 4‐fluorobenzoyl chloride in nitrobenzene selectivity afforded 1 in 82% yield. X‐ray single crystal structural analysis of 1 confirmed that the dibenzoylation proceeded regioselectively and two methyl groups sterically inhibited the coplanarity of the two aromatic planes. The polycondensation of 1 with Bisphenol A in toluene/N‐methyl‐2‐pyrrolidone (NMP) mixed solvent in the presence of excess potassium carbonate as a condensation reagent was carried out at 180°C for 4 h to quantitatively afford the corresponding poly(arylene ether‐ketone) (PEK) 3 with high molecular weight (M̄n∼30,000) as a slightly yellow powder. As the reaction time was prolonged, both M̄n and MWD of 3 increased and the solubility of 3 in chloroform clearly decreased. By GPC‐LALLS, M̄n of 3 obtained by the polycondensation for 16 h, was 85,000. The PEK 3 with high molecular weight was produced in a quantitative yield in a variety of solvents such as sulfolane. Water formed during the polycondensation hardly affected the yield and molecular weight of 3, although a small molecular weight decrease took place. To evaluate the special effect of the methyl groups of 3, polycondensation of 2,6‐bis(4‐fluorobenzoyl)naphthalene 2 with bisphenol A was carried out for comparison and the corresponding PEK 4 was quantitatively obtained. Whereas 3 was soluble in ordinary organic solvents such as tet‐rahydrofuran (THF), chloroform, and NMP at room temperature, 4 was insoluble in most solvents except for strong acids such as conc. sulfonic acid. The polymer 3 showed high glass transition temperature (238°C) and 5% weight loss temperature (457°C). Casting of the polymer from THF solution gave a transparent, tough, flexible, and amorphous film. © 1995 John Wiley & Sons, Inc.

Powerful solvent systems useful for synthesis of sparingly-soluble peptides in solution.

Our maximum protection strategy for the synthesis of human parathyroid hormone(1-84) indicates that fully protected peptide segments in the form of Boc-peptide phenacyl (Pac) ester are relatively soluble in ordinary organic solvents such as DMF, NMP or DMSO, which are suitable for coupling segments. However, about 1% of such segments synthesized were found to be insoluble even in the most polar solvent, DMSO. Thus, a more powerful solvent which can be used for their peptide synthesis was pursued. Among the solvent systems tested, a mixture of trifluoroethanol (TFE) or hexafluoroisopropanol (HFIP) and trichloromethane (TCM) or dichloromethane (DCM) was found to be most powerful for dissolving such sparingly-soluble protected peptides. These solvent systems were confirmed to be useful for the removal reaction of the carboxy-terminal Pac esters from the sparingly-soluble segments. They were then tested for the coupling reactions of fully protected Boc-peptides with other sparingly-soluble peptide esters. The TFE/TCM or TFE/DCM system was extremely useful for coupling segments without danger of racemization and of trifluoroester formation, if WSCI was used as the coupling reagent in the presence of 3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine (HOOBt).

Purification procedures for synthetic dyes: Part 4—Flash chromatography

The suitability of flash chromatography for the purification of synthetic dyestuffs has been investigated. The results of this study indicate that this technique offers a rapid procedure for the generation of gram quantities of a disperse dye, provided the dye to be purified is reasonably soluble in ordinary organic solvents such as toluene, ethyl acetate, or hexane. It is also apparent that the water-containing eluents commonly used to develop hydrophilic dyestuffs do not give satisfactory results when silica gel is used, due to strong eluent-adsorbent interactions. As a consequence, the purification of hydrophilic dyes required deactivated alumina. The speed with which a purification is accomplished by flash chromatography often offsets the higher amount of solvent required compared with the amounts used in dry column chromatography and countercurrent chromatography.

Distribution Equilibria of Metal Chelates with Thiazolylazo Dyes between Two Phases Formed from an Aqueous Micellar Solution of a Nonionic Surfactant

A dilute aqueous micellar solution of poly(oxyethylene)=4-nonylphenyl=ether with oxyethylene units of 7.5 (average, PONPE-7.5) was separated into two phases (aqueous and surfactant) at room temperature. The partition constants of thiazolylazo dyes and their metal chelates between the two phases were determined at 293K and an ionic strength of 0.1(NaClO4). Though a linear relationship was obtained between the partition constants of the chelating reagents in the extraction with PONPE-7.5 and those in the ordinary extraction with octanol, such a relationship was not obtained for the chelates. This suggested that the properties of the PONPE-7.5 phase as an extracting solvent were different from those of ordinary organic solvents.

Synthesis and properties of 4‐hydroxy‐2,3,5,6‐tetrabromobenzyl phosphonates and effects of their flame retardance on impact polystyrene

Abstractp‐Cresol was converted into 2,3,5,6‐tetrabromocresol by AlCl3 catalyst bromination, and then further brominated to 4‐hydroxy‐2,3,5,6‐tetrabromobenzyl bromide (HTBBB) in benzene by light. HTBBB reacted easily with trialkyl phosphite to produce 4‐hydroxy‐2,3,5,6‐tetrabromobenzyl phosphonates (HTBBPs) in solvents. Although the reaction of HTBBB with triaryl phosphite was slower than that with trialkyl phosphite, it does produce corresponding phosphonate with ease. Except for DMF, DMAc, chloroform, and tetrahydrofuran, HTBBP was difficult to dissolve in ordinary organic solvents. Of all the synthesized HTBBP, dimethyl hydroxy‐2,3,5,6‐tetrabromobenzyl phosphonate showed the poorest solubility. With the addition of these new compounds containing bromine and phosphorus atoms to HIPS as flame retardants, the results of oxygen index measurement showed that the flame resistance of these compounds was greater than the additive effect of the two corresponding individual brominated compound and phosphorus‐containing compound. It means that these new compounds seem to act synergistically as flame retardants in HIPS. Simultaneous addition of bominated compound and phosphorus‐containing compound to HIPS ends up with a similar effect as mentioned above, but the new compounds can prevent the exclusion of phosphorus‐containing compound from polymer matrix.

Soluble conducting polythiophenes

Tractable polythiophenes which are soluble in ordinary organic solvents at ambient temperatures are prepared by the electrochemical polymerization of thiophenes having a long alkyl chain.

Exploratory ring‐opening polymerization. XIIL ring‐opening polymerization of 2‐vinyl cyclic sulfones

Abstract2‐Vinyllhiolane‐1,1‐dioxide (Ia) and 2‐vinylthiane‐1,1‐dioxide(Ib) have been prepared and polymerized with free radical initiators to obtain poly(sulfonyl‐hex‐2‐enylene) (IIa) and poly(sulfonyl‐hept‐2‐enyIene‐co‐2‐vinylthiane‐1,1‐dioxide) (IIb), respectively, via a ring‐opening mechanism. Structures of the polymers are supported by infrared and 1H‐NMR spectroscopy. Poly(sulfonyl‐hex‐2‐enylene) was insoluble in ordinary organic solvents, but soluble in concentrated sulfuric acid or trifluoroacetic acid, and was white amorphous powder, softening at 168°C. Degradation occurred at 294°C under N2. Ia copolymerized with certain vinyl monomers, such as ethyl acrylate, but its copolymerization behavior was different from those of normal vinyl monomers.

Investigation of the decomposition of 1,3-diaryl-5-(3-chloro-2-quinoxalyl)-formazans by PMR and MASS spectrometry

In contrast to triarylformazans, 1,3-diaryl-5-(3-chloro-2-quinoxalyl)formazans are unstable in ordinary organic solvents. When they are heated in chloroform, they undergo acidic cleavage, which leads to the formation of 3-chloro-2-quinoxalylhydrazones of p-substituted benzaldehydes and arenediazonium cations. These compounds, as a result of a redox reaction with the participation of the solvent, are converted to 4-chloro-1-(4-Y-phenyl)-1,2,4-triazolo[4,3-a]quinoxalines, substituted benzenes, nitrogen, and hydrogen chloride. The formation of the latter transforms the entire decomposition process into an autocatalytic process. Effects of chemical polarization of the nuclei (CPN), which unambiguously indicate the intermediate formation of diazoaryl radicals during the process, are observed in the PMR spectra of the final products. Such CPN effects, which were also observed in dimethyl sulfoxide (DMSO) and glacial acetic acid, indicate a process involving the oxidative formation of annelated triazoles from α-azahetarylhydrazones via a radical pathway within a solvent “cage.”

Molecular weight determinations of polyamides by N-trifluoroacetylation

By N-trifluoroacetylation (TFA) polyamides become soluble in ordinary organic solvents such as acetone, butanone, methylene chloride, chloroform and tetrahydrofuran. In these solvents light scattering and osmotic measurements (membrane and vapour-phase osmometry) were carried out to determine the weight and number average degrees of polymerization. Comparison with the results on non-TFA-polyamides in various solvents clearly shows that no polymer degradation takes place. The [ η]- P relationships of Trogamid R-TFA and nylon-6-TFA in tetrahydrofuran at 25°C were determined and corrected for polydispersity.

Synthesis of polyamides containing cytosine and hypoxanthine

AbstractThe di(cyanomethyl) methylsuccinate derivative of cytosine and di(p‐nitrophenyl) methyl‐succinate derivative of hypoxanthine were prepared and polycondensed with a variety of diamines to provide powdery polyamides with molecular weights in the range of 1000–3100. The polyamides are soluble in DMSO and formic acid, but insoluble in ordinary organic solvents.

On the preparation of oligo (Arylene sulphides) by a transarylation reaction

A novel method has been developed for the preparation of oligo- and poly-arylenesulphides by reactions of transarylation of diphenyl sulphide (DPS) in presence of aluminium chloride used as catalyst. The resulting oligoarylen ensulphides have softening points at 110–120°, and dissolve in ordinary organic solvents. The results of investigations based on IR spectroscopy, mass spectroscopy and elemental analysis, along with those of polymer analogue transformations with subsequent analysis of thermal degradation products of the polymer analogues show that structurallyv the oligomeric products of transarylation of DPS are skin to intramolecular cyclic sulphides in which thianthrene fragments predominate. The oxidation of these oligomers resulted in ologoarylene sulphones of cyclic structure possessing higher heat resistance and thermal stability.

Polybenzimidazoles with benzimidazolyl side groups

Polybenzimidazoles with benzimidazolyl side groups and containing hinge groups (-O-, -SO 2-, -CO-, -CH 2-) in one or both components, have been prepared by reacting bisbenzoylenebenzimidazoles with tetramines in polyphosphoric acid. The relationship between the chemical structure and physicochemical properties of the polymers was studied. It is shown that the introduction of benzimidazolyl substituents makes the polymers become amorphous and reduces their heat distortion temperature without having any appreciable effect on their resistance to thermal oxidation. The solubility of the polymers in ordinary organic solvents is increased to some extent.

Analyses of drugs and chemicals by infrared absorption spectroscopy. XI. Determination of saccharin sodium, dulcin, and sodium cyclamate in their mixture by use of methanol and water as solvents

New infrared spectrophotometric methods are offered for rapid determination of saccharin sodium, dulcin, and sodium cyclamate in their mixture. These components are sparingly soluble in ordinary organic solvents used in infrared analyses, and methanol and water are chosen as solvents. In methanol solution, the absorption bands at 1149 and 1512 cm-1 are used for the determination of saccharin sodium and dulcin, respectively, and in aqueous solution, the absorption band at 1194 cm-1 is used for the determination of sodium cyclamate. These methods gave good results in different standard mixed samples and these are very useful for routine analyses with simple operation.

Fractionation and characterization of wax D, a macromolecular peptidoglycolipid of Mycobacterium tuberculosis: I. Biochemical investigations of wax D of human strain H 37Ra

1. 1. Acetylation of wax D, a macromolecular peptidoglycolipid of Mycobacterium tuberculosis, proceeds smoothly at room temperature and makes the further chromatographic separation of wax D into three main groups possible. 2. 2. These groups consist of: (1) four fractions free from amino acids (30%), (2) two fractions containing only glutamic acid, alanine and diaminopimelic acid (30%), and (3) one fraction containing many amino acids including those which had not hitherto been recognized in wax D (14%). 3. 3. Direct measurement of the molecular weight of the sub-fractions of acetylated wax D by a surface-balance technique gives precise values, 4. 4. Acetylated wax D remains soluble in ordinary organic solvents, which facilitates further purification. 5. 5.Information about a possible biological role played by the hydroxyl groups of wax D is obtainable through acetylated wax D.

Structure of Cupric Mono-, Di- and Tri-bromoacetates

IT was concluded in our former communication1 that cupric mono- and di-chloroacetates in the crystalline state and in ordinary organic solvents might consist of the binuclear molecules with a sort of copper-to-copper linkage, though cupric trichloroacetate does not have a similar binuclear molecule in the crystalline state or in dioxan. The exceptional structure of cupric trichloroacetate may be ascribed to the accumulation of the inductive effect of the three chlorine atoms. In this connexion, it seems interesting to see what type of structure may be involved in the cupric bromoacetates. Therefore, we examined the structure of cupric mono-, di- and tri-bromoacetates, using the criteria previously derived: (1) the cupric monocarboxylates involving the binuclear molecules show, in addition to a band at about 40 to 44 × 1013 c./s., a special absorption band at about 80 × 1013 c./s., which was regarded as possibly due to the presence of the copper-to-copper linkage; (2) the polarization of the latter band is the reverse of the polarization of the former.