Terephthalaldehyde, reaction with

A related catalyst type where the metal centre is supported by a longer spacer chain has been reported (Figure 4.3).64,65 This material was prepared from aminopropyl-silica by reaction with terephthalaldehyde to form the mono-imine (attachment of the amine to the surface precludes reaction at both ends of... 

Wojtkonski [185] has also reported on three series of melt spinnable thermotropic aromatic-aliphatic polyimines. The polyimines were prepared by reaction of 1,2-bis(4-formylphenoxy) ethane, terephthalaldehyde, or 4,4 -biphenyldicarboxaldehyde, respectively, with l,n-bis(4-amino-3-methylphenoxy) alkanes where n = 1-10, 12, 14, and 16 in dry DMAC containing 5% dry lithium chloride. The polymers decomposed at 400°C, and as the length of the flexible aliphatic segments increased, melting points decreased. Polymers with an odd... 

Several silver(I) complexes of the macrocyclic Schiff base derived from the [2+2] condensation of terephthalaldehyde and 3-azapentane-1,5-diamine or A,A -bis(3-aminopropyl)methylamine have been described.509,510 The reaction of 2,ll-diaza-difluoro-m-[3,3]-cyclophane with 2,6-bis (bromomethyl)pyridine lead to the 3 + 3 addition product, which gives a complex with two silver... 

Novel fluorine-containing aromatic poly(azomethine)s are prepared by the reaction of hexafluoroisopropylidene-unit-containing aromatic diamines, 2,2-bis[4-(4-aminophenoxy)phenyl]-l,l,l,3,3,3-hexafluoropropane (17) and 2,2-bis(4-aminophenyl)-l, 1,1,3,3,3-hexafluoropropane (18) with terephthalaldehyde (19) or isophthalaldehyde (20)20 (Scheme 11). 

The dication 212+ composed of two methylium units connected to a p-phenylene spacer would be a candidate for new Wurster type violene-cyanine hybrid (Figure 12) (15). The reaction of four molar amounts of azulene 6b with terephthalaldehyde yielded the hydro precursor. Synthesis of the dication 212+ was accomplished by hydride abstraction with DDQ in almost quantitative yield. The dication 212+ was expected to show destabilization, but instead it exhibited high thermodynamic stability just like the corresponding monocation 3b+. 

B) 2PiCH3 +C6H5CHO (PiCH2)2CHC6Hs Both reactions are catalyzed by piperidine reaction (B) is run in pyridine, reaction (A) in aromatic solvents such as benzene or toluene, A series of monosubstituted benzaldehydes react similarly via reaction (A) (Ref 23) as do also terephthalaldehyde (Ref 23), and isophthal-aldehyde (Ref 117), both with two moles of TNT. A similar product could not be made from phthalaldehyde (Ref 117), and only traces of HNS were obtained from TNT and 2,4,6-trinitrobenzaldehyde (Ref 31)... 

Electroanalytical techniques indicate the formation of two carbinolamine intermediates and one monohydrazone in the reaction of terephthalaldehyde with hydrazine at pH 7.3.91... 

Diethylzinc was used as a catalyst for the preparation of polyesters from terephthalaldehyde via the Tischenko reaction (480), and for the polycondensation of ethylene glycol with dimethyl terephthalates to afford polyethylene terephthalate (340). Benzylzinc chloride has been used as a catalyst for polycondensation of benzyl chloride (223). 

Structurally uniform polymeric porphyrins are expected if terephthalaldehyde is reacted with pyrrole in boiling propionic acid. Polymers from this reaction have been described [53], The authors cleaned the product from polypyrrole and low molecular weight porphyrins by washing with methanol and chloroform, and introduced different metal ions by treatment with metal salts in an ethanol/water mixture. But the polymers which exhibited specific conductivities of 10 S cm (up to 10 S cm by doping with I2) were analyzed only by IR-spectra. 

Notably, l,4-bis(trifluoromethyl)benzene is commercially available. It is synthesized from terephthalaldehyde, in a two step reaction. In the first step, terephthalaldehyde is reacted with sulfur tetrafluoride at 150 C under pressure to give tetrafluoro-p-xylene. In the second step, this compound is brominated by a photolysis reaction in the presence of fV-bromo succinimide. 

PPV (27a) has been prepared by a number of different methods which were studied in detail by Horhold and Opfermann [129]. It can be synthesized by bifunctional carbonyl olefination of terephthalaldehyde according to Wittig s reaction and from /)-xylylene-bis-(diethyl phosphonate) as well as by dehydrochlorination of p-xylylene dichloride with sodium hydride in N,N-dimethylformamide and with potassium amide in liquid ammonia. Another route to PPV used today is the precursor route, first described by Wessling [130 133] and Kanabe [134], starting from the monomers /)-xylylene-bis(dimethylsulfo-nium tetrafluoroborate) [134] or chloride (Scheme 28) [130-133],... 

A new DOPO-containing compound with complex architecture, namely bis((6-oxido-6H-dibenz[c,e][l,2]oxaphosphorinyl)-(4-hydroxyaniline)-methylene)-l,4-phenylene XVI, was prepared by us in a two-step procedure, treating 4-aminophenol with terephthalaldehyde in the first step, followed by the phosphorylation reaction of its imine linkages with DOPO molecules (Scheme 14.8). 

The polymerization of a,P-unsaturated carbonyl compounds is very similar to the Friedel-Crafts synthesis of aromatic ketones, where tiie catalyst forms a complex with the reaction products and therefore is necessarily to be used in equimolecular amount. In order to avoid the WCle consumption via doping of polyacetylenes we tried to perform COER with highly substituted olefins (tetraphenylethylene, stylbene, 1,1-diphenylethylene) and simple carbonyl compounds (benzophenone, terephthalaldehyde) using WClfunctional groups are in different molecules and the results should be new olefins and new carbonyl compounds, not a conjugated... 

Melamine reacts with several other aldehydes as well as with alcohols to give etherified products. Most other aldehydes give resinous products that have not been fully characterized. Rudelburgher reacted melamine (2 moles) with glucose (1.0 mole) to obtain a derivative melting at 218°C [69]. The synthesis of a curable melamine-acetaldehyde resin was reported by Henkel Co. [70]. The reaction of melamine with aldehydes such as benzaldehyde, cinnamaldehyde, hexahydrobenzaldehyde, terephthalaldehyde, and acrolein have been reported [71]. 

The reaction of 2,5-dimethylpyridine with terephthalaldehyde [Eq. (1-7)] yielded a crystalline polymer that softened at 210°C and possessed a specific viscosity of 0.21 (H2SO4). The structure [13] of this polymer was in agreement with chemical and spectroscopic evidence 44). It had aldehydic termination its molecular weight determined by elemental analysis of its thiosemicar-bazone was 5000. This polymer is soluble in several solvents sulfuric and hydrochloric acids, benzyl alcohol, pyridine, quinoline, and m-cresol. When the polycondensation was performed at higher temperature (210°-220°C), an insoluble polymer was obtained. Whether the insolubility was due to a higher molecular weight polymer was not determined. 

PPV (62a) has been prepared by a number of different methods which were studied in detail by Horhold and Opfermann [390]. It can be synthesized by bifunctional carbonyl olefination of terephthalaldehyde according to Wittig s reaction and from />-xylylene-bis(diethyl phosphonate), as well as by dehydrochlorination of/p-xylylene dichloride with sodium hydride in A jiV-dimethylformamide and with potassium amide in liquid ammonia. The most popular route to PPV used today is the precursor route, first described by Wessling and Zimmermann [391-394] and Kanabe and Okawara [395], starting from the monomers p-xylylene-bis(di-methylsulphonium tetrafluoroborate) [395] or chloride (Scheme 11.17) [391-394]. The latter is polymerized to yield a water soluble sulphonium salt polyelectrolyte (63d) which is then purified by dialysis [396]. The precursor polymer is converted to PPV (63e) by the thermal elimination of dimethyl sulphide and HCl. The method was later developed by Horhold et al. [397], Lenz and co-workers [398,399], Murase et al. [400] and Bradley [401], One of the major improvements within the last years has been the use of tetrahydrothio-phene instead of dimethyl sulphide in the synthesis of the precursor polymer [402]. The use of the cyclic leaving group facilitates the elimination when the precursor polymers is heated at 230-300°C and leads... 

Furthermore, they integrated two distinct enantioselective chiral Zn(II) catalyses, HDA and diethylzinc addition reactions, in one pot in a sequential manner (Scheme 4.27). The desired product was obtained with both dihydropyranone and secondary alcohol moieties from terephthalaldehyde in excellent selectivity (> 93% yield, 97.4% ee) by using 10mol% of the combined catalyst (87)/Zn(II)/(92). 

Poly(p-phenylene vinylene)s have been synthesized by various methods, such as the reaction of p-xylene-bis(triphenylphosphonium chloride) with terephthalaldehyde in the presence of lithium ethylate (Wittig reaction) [64], the reaction of p-xylene tetrabromide with alkyllithium in tetrahydrofuran [65], and the polymerization of a precursor polymer [66]. Poly(p-xylyli-dene)s have been synthesized by dehydrochlorination of p-xylene dichloride with sodium hydride in dimethylformamide [67]. 

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