0-Hydroxyphenyl phenyl ether

Certain arylalkyl ethers, with which cleavage by acid fails or leads to undesired by-products, can be decomposed by alkalis or alkoxides at temperatures above 150°, preferably with addition of ethanol or a higher-boiling alcohol. Veratrole, for instance, can be partially converted into guaiacol by 3 hours heating with equal parts of potassium hydroxide and ethanol 31 and 0-meth-oxyphenyl phenyl ether is cleaved to 0-hydroxyphenyl phenyl ether in 91% yield by 10 hours boiling with sodium hydroxide in diethylene glycol.32... 

Transalkylation reactions under acidic conditions have been reported for 2,2-bis(4-hydroxyphenyl)propane with 2,6-dialkylphenol [97], 2,6-diphen-ylphenol [98], diphenyl ether [99], and with 4-bromophenyl phenyl ether [99]. For example, the reaction of 2,2-bis(4-hydroxyphenyl)propane and a 2,6-disubstituted phenol is shown in Fig. 29. 

Typical of this work is the rearrangement of phenyl p-toluenesulphonate into 2-hydroxyphenyl and 4-hydroxyphenyl p-tolyl sulphones274. Ogata and coworkers275 have shown that phenyl benzenesulphonate also rearranges on irradiation in ethanol and yields both 2-hydroxyphenyl and 4-hydroxyphenyl phenyl sulphones as well as phenol, small amounts of diphenyl ether and polymer. Interestingly, the tolyl derivative 305 does not rearrange and only o- and p-cresol are isolated. Irradiation (330 nm) of the sulphonates 306 in ethyl acetate affords the hydroxysulphones 307 in 66% yield. The reaction of 306 also... 

Alkylation of phenols and rearrangement of phenyl ethers. 4-Hydroxybu-tanone serves as an alkylating agent, giving 4-(4-hydroxyphenyl)-2-butanone in 28% yield on heating with phenol in the presence of Zr(IV)-montmorillonite at 100°C for 48 h. The same compound is obtained in 34% yield when 3-oxobutyl phenyl ether is treated with Zn(II)-montmorillonite and phenol. ... 

S.H. Hsiao, W.T. Chen, Syntheses and properties of novel fluorinated polyamides based on a fci5(ether-carboxyUc acid) or a bisiether amine) extended from feiX4-hydroxyphenyl) phenyl-2,2,2-trifluoroethane, J. Polym. Sci. Part A Polym. Chem. 41 (3) (2003) 420-431. 

Phenyl ether see 4-Hydroxydiphenyl Ether. Benzyl ether p-Hydroxyphenyl beaizyl Ether. Diaeetyl plates from EtOH. M.p. 121° (123-4°). Very sol. EtgO, CHC1 hot EtOH. Sol. hot HgO. 

Crystallisable polymers have also been prepared from diphenylol compounds containing sulphur or oxygen atoms or both between the aromatic rings. Of these the polycarbonates from di-(4-hydroxyphenyl)ether and from di-(4-hydroxy-phenyl)sulphide crystallise sufficiently to form opaque products. Both materials are insoluble in the usual solvents. The diphenyl sulphide polymer also has excellent resistance to hydrolysing agents and very low water absorption. Schnell" quotes a water absorption of only 0.09% for a sample at 90% relative humidity and 250°C. Both the sulphide and ether polymers have melting ranges of about 220-240°C. The di-(4-hydroxyphenyl)sulphoxide and the di-(4-hydroxy-phenyl)sulphone yield hydrolysable polymers but whereas the polymer from the former is soluble in common solvents the latter is insoluble. 

After 6 hours the calculated amount of hydrogen has been taken up. The residue obtained after filtering and evaporating is taken up in benzene and extracted twice with diluted sodium carbonate solution. The alkali extract is then made acid to Congo red with 6N hydrochloric acid and the precipitate is taken up in ethyl acetate. The solution obtained is washed twice with salt solution, dried with sodium sulfate and evaporated. The residue is recrystallized from ether/petroleum ether. 1-(p-hydroxyphenyl)-2-phenyl-4-n-butyl-3,5-dioxo-pyrazolidine melts at 124° to 125°C. 

Herbert and Hay reported a bisphenolic monomer, 3,8-bis(4-hydroxyphenyl)-A-phenyl-1,2-naphthalimide (Table 6.1), as well as its corresponding polyf V-phenyl imido aryl ether sulfone) via transimidization reactions with hydrazine monohydrate, aliphatic amines, and an amino acid.193 These polysulfones with... 

Poly(arylene ether)s containing phenylimidazole units were initially prepared from the reaction of 2-phenyl-4,5-di(4-hydroxyphenyl)imidazole and various activated aromatic difluoro compounds according to Eq. (4) [20]. The dihydroxyimidazole was first prepared from the reaction of 4,4 -dimethoxyben-zil, benzaldehyde and ammonium acetate in refluxing acetic acid followed by... 

Poly(arylene ether benzoxazole)s were also synthesized from the reaction of bis[(4-hydroxyphenyl)benzoxazole]s and activated aromatic difluoro monomers as shown in Eq. (7) [28,29]. The bis[(4-hydroxyphenyl)benzoxazole]s were readily prepared by condensation of the appropriate bis(o-aminophenol) (e.g. 3,3 -dihydroxy-4,4 -diaminobiphenyl) with phenyl-4-hydroxybenzoate in diphenyl sulfone at 260°C. Under proper conditions, the less expensive 4-hydroxybenzoic acid can be used in place of the phenyl ester to provide high yields of the desired bis[(4-hydroxyphenyl)benzoxazole]s. As presented in Table 9, the hexafluoroisopropylidene (6F) containing polymers were amorphous. These polymers were prepared in DMAc. However, the polymers derived from 6,6 -bis[2-(4-hydroxyphenyl)benzoxazole] were prepared in diphenyl sul-... 

Poly(arylene ether l,2,4-triazole)s were synthesized from the reaction of 3,5-di(4-hydroxyphenyl)-4-phenyl-1,2,4-triazole with three different activated aromatic difluoro monomers [34,35]. The polymer from the triazole bisphenol and 1,4-di(4-fluorobenzoyl)benzene exhibited an inherent viscosity of 3.40 dL/g (0.5% solution in m-cresol at 25 °C), a Tg of 216 °C and a Tm of 377 °C [35]. Solution cast amorphous unoriented thin films of this polymer gave 23 °C tensile strength, modulus and elongation of 87.6 MPa, 2.7 GPa and 7.8% respectively. No work was performed to induce crystallinity in the film. 

Poly(arylene ether benzimidazole)s have received more attention than any other PAE containing heterocyclic units. This is due primarily to their unique combination of properties even at relatively low molecular weights and their potential for use in several high performance applications. The initial report in 1991 involved polymers from the reaction of 3 different bis[(4-hydroxy-phenyl)benzimidazole]s with various activated aromatic difluoro monomers as shown in Eq. (10) [37]. The bis[(4-hydroxyphenyl)benzimidazole]s were prepared from the reaction of aromatic bis(o-diamines) and phenyl-4-hydroxybenzoate in diphenyl sulfone. The use of 4-hydroxybenzoic acid would obviously reduce the... 

Entry 9 in Table 3.13 is an example of a safety-catch linker, which requires activation by TFA-mediated cleavage of a tert-butyl ether. The unactivated 2-(tm-butoxyj-phenyl esters are cleaved by amines 700 times more slowly than the corresponding 2-hydroxyphenyl esters [289]. A similar linker has been described [290], in which a benzyl ether is used instead of a ferf-butyl ether. Activation of this linker by debenzy-lation was achieved by treatment with HF or HBr/TFA [290]. 

Many works on the synthesis of cyclic polymers and block copolymers using kinetically controlled ring-expansion polymerizations of cyclic monomers, such as lactones and lactides with various types of cyclic tin initiators, were reviewed by Kricheldorf [147,148]. Kricheldorfs group continued the synthesis of cyclic polymers, and their recent works have focused on the following. Polycondensations of 4,4/-difluorodiphenylsulfone with tris(4-hydroxy phenyl)ethane were performed in DMSO to give multi-cyclic poly(ether sulfone)s derived from tris(4-hydroxyphenyl)ethane [149]. 

Six more polyaryl ethers were made from 2,6-dichlorobenzonitrile (2) and one of the following monomers l,l -bis(4-hydroxy-3,5-dimethyl phenyl) cyclohexane 2,2 -bis (4-hydroxyphenyl) -2-phenyl ethane 1,3-bis(4-hydroxyphenyl)-1-ethyl cyclohexane 2- ( hydroxyphenyl)-2-[3-(4-hydroxyphenyl) -4-methyl cyclohexyl ] propane 2,2 -bis (4-hydroxy-3,5-dimethyl phenyl) propane and bisphenol A. 

Hydroxyphenyl)-telliirophene 0.92 g (11 mmol) of sodium ethanethiolate are dissolved in 9 ml of dimethylformamide (DMF), the solution is stirred under nitrogen, and 0.4 g (1.4 mmol) of 2-(4 -meth-ox) phenyl)-tellurophene in 9 ml of DMF are added. The mixture is heated at 80° for 144 h, cooled, diluted with water, and extracted with diethyl ether. The aqueous phase is acidified with 10% hydrochloric acid, the acidified aqueous phase is extracted with diethyl ether, and the organic extracts are combined, dried with anhydrous sodium sulfate, filtered, and concentrated under vacuum. The residue is chromatographed on silica gel with light petroleum ether (b.p. 40-60°)/diethyl ether (4/1, v/v) as the mobile phase. The product is recrystaUized from ligroin/chloroform (1/1, v/v) yield 0.1 g (26%) m.p. 160 . 

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