Transmission of polar effects through aromatic systems. III. Hammett σ-constants was written by Norman, R. O. C.;Radda, G. K.;Brimacombe, D. A.;Ralph, P. D.;Smith, E. M.. And the article was included in Journal of the Chemical Society in 1961.Synthetic Route of C10H11FO2 This article mentions the following:
Hydrolysis of Et phenylacetate (I) and nine monosubstituted derivatives in aqueous Me2CO at 25° were measured. The results supported the theory of van Bekkum, Verkade, and Wepster (CA 54, 16407g) that mesomeric p-interaction between substituent and functional center may affect the σ-value of a substituent. Variations in σ-values arising from the polar effect of the substituent on the resonance interaction of the functional center with the aromatic nucleus were noted. An improved method of obtaining σ-values was proposed in which use was made only of those reaction series where resonance interaction between the functional center and the aromatic ring was precluded. Substituted phenylacetic acids were prepared by known methods and converted into their Et esters. Liquid esters were purified by fractional distillation and the solid esters recrystallized from ligroine. The following phenylacetic acids and their Et esters were obtained (substituent, m.p. of acid, m.p. of Et ester, b.p./mm. of Et ester given): H, -, -, 227°/758; m-Me, 62°, -, 122-3°/18; m-NO2, 118-20°, 11.5-12.5°, 127-35°/0.25; p-Me, 94°, -, 134-5°/25; p-OMe, 85-6°, -, 143-4°/11; p-F, 84.5°, 34°, 128-30°/31; p-Cl, -, 33-3.5°, -; p-Br, -, 31.0-1.5°, -; p-COMe, -, 62-3°, -; p-NO2, -, 63°, -. The procedure for rate measurements was that described by Tommila and Hinshelwood (CA 33, 11996). Atm. CO2 was excluded by alkali solutions and these were restandardized frequently. Initial concentrations of alkali and ester were equal and the extent of hydrolysis was studied from 10-80% completion. Each reaction obeyed 2nd order kinetics. The following rate constants (l. mole-1sec.-1) for the alk. hydrolysis of Et phenylacetates at 25° were obtained (substituent, and 102k given): II, 4.40; m-Me, 3.58; p-Me, 3.18; p-OMe, 3.93; p-F, 6.96; p-Cl, 9.71; p-Br, 10.10; p-COMe, 13.0; m-NO2, 18.4; p-NO2, 26.2. The following σn and σG values were obtained (substituent, σn, and σG given): p-Me, -0.129, -0.129; m-Me, -0.069, -0.105; p-OMe, -0.111, -0.097; p-F, 0.168, 0.143; p-Cl, 0.238, 0.256; p-Br, 0.265, 0.281; m-Cl, 0.373, 0.334; m-NO2, 0.710, 0.576; p-NO2, 0.778, 0.708. The σG and ρ values were obtained from the following reactions (reaction, solvent, temperature, ρ, s, r, n given): ArCH2CO2Et + OH–, 60% Me2CO, 25°, 1.069, 0.029, 0.996, 8; ArCH2CO2Et + OH–, 85.4% alc., 24.8, 1.168, 0.021, 0.998, 5; ArCH2CO2H (pKa), H2O, 25°, 0.612, 0.027, 0.989, 8; ArCH2OHc + OH-1, 56% Me2CO, 25°, 0.894, 0.019, 0.998, 8; ArCH2NHAc + Cl2, 40% AcOH, 18, -1.256, 0.049, 0.987, 5. In the experiment, the researchers used many compounds, for example, Ethyl 2-(4-fluorophenyl)acetate (cas: 587-88-2Synthetic Route of C10H11FO2).
Ethyl 2-(4-fluorophenyl)acetate (cas: 587-88-2) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Liquid esters of low volatility serve as softening agents for resins and plastics. Esters also include many industrially important polymers. Polymethyl methacrylate is a glass substitute sold under the names Lucite and Plexiglas; polyethylene terephthalate is used as a film (Mylar) and as textile fibres sold as Terylene, Fortrel, and Dacron.Synthetic Route of C10H11FO2
Referemce:
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