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Analogs, benzene

Figure 4. Electronic spectra of analogous benzene amd thiazole azo dyes. Figure 4. Electronic spectra of analogous benzene amd thiazole azo dyes.
Positions marked B show reactivity comparable to that of ring carbons in benzene. Substituents can be introduced by electrophilic substitution reactions (Section 3.4.1.4) and show reactivity similar to those of the analogous benzene. Thus, amino groups can be diazotized (Section 3.4.3.5.3) and halogens are unreactive. [Pg.706]

Unsubstituted benzofuran and dibenzofuran show very intense peaks of the molecular ions,22b reflecting their high stability, caused by the lack of bonds which can be cleaved easily. The spectra of benzofurans substituted with a methyl group in the benzene ring (15) are characterized by abundant ions at M-l. They are assumed to have the oxonium ion structure [17] (see Budzikiewicz,11 p. 230) rather than that of a tropylium ion [16],22b as might be supposed considering the decomposition of analogous benzene compounds.22b... [Pg.307]

Schleyer proposed one last alternative method for ganging ASE. Noting that many of these better methods (especially those analogons to Reaction 3.24) require computation of many compounds, he developed the isomerization stabilization energy (ISE) method, particularly useful for strained aromatic systems. ISE measures the energy realized when an isomeric compound converts into its aromatic analog. Benzene itself cannot be analyzed by the ISE method, however, toluene can, and the ASE values of toluene and benzene are expected to be quite similar. The conversions of two different isomers into toluene provide the ISE for toluene (Reactions 3.27a and 3.27b). Both of these reactions do not conserve s-cis/s-trans diene conformations. Reaction 3.28 can be added once to Reaction 3.27a and twice to Reaction 3.27b to give the corrected ISE values of -32.0 and -28.9 kcal mol , respectively. [Pg.149]

For reviews of the norcaradiene-cycloheptatriene interconversion and the analogous benzene oxide-oxepin interconversion, see Maier, G. Angew. Chem. Int Ed. 1967, 6, 402 Vogel, E. Gunther, H. Angew. Chem. Int. Ed. 1967, 6, 385 Vogel, E. Pure Appl. Chem. 1969, 20, 237. [Pg.1633]

Sometimes the interactions typical for 1.2-disubstituted arenes have a formal correspondence in the decompositions of 2.2 substituted biphenyl derivatives. Thus the highly specific piperidine eliminations from 14330 as well as the formation of 146 correspond to the fragmentations of structurally analogous benzene derivative. [Pg.257]

In continuous-flow, liquid phase runs, high conversions of 1-decene to mixtures of decylbenzene isomers occurred in reaction with benzene over REX catalyst (Fig. 25). In analogous benzene alkylation attempts with 1-decene or 1-decanol at atmospheric pressure, side reactions of... [Pg.324]

Homologues of thiophene occur in coal-tar they may be prepared by Fittig s synthesis and in other ways. Their properties are similar to those of the analogous benzene derivatives for example, thiotolene, methyl thiophene, is converted into thiophene carboxylic acid by oxidizing agents —... [Pg.576]

The important influence of the substitution pattern upon the sign of the a-band CD within 3 series of homochirally analogous benzene derivatives shows fig. 3. The data are in part from the literature (ref. 7) and in part our own ... [Pg.69]

The transition temperatuies of compound 24 reveal the cyclohexane core to be better at generating columnar mesophases (thought to be hexagonal) than the analogous benzene systems. This is not surprising given the strong liqnid crystal tendency of calamitic... [Pg.90]

Borazines are much more reactive than analogous benzene compounds. A marked difference from benzene which reflects the polarity of the ring bonds is that borazine adds water, methanol, alkyl iodides and hydrogen halides, the negative parts of which become attached to the borons ... [Pg.88]

The synthesis of the cyclooctatetraene dianion fused at the [e]-position of trans-10b,10c-dimethyl-10b,10c-dihydropyrene (1) has been described, and by comparison of H NMR properties and nucleus-independent chemical shifts to the analogous benzene-fused dihydropyrene (2), the relative aromaticity of the dianion has been found to be at least as great as that of benzene and substantially larger than that of the cyclopentadienide anion. ... [Pg.307]


See other pages where Analogs, benzene is mentioned: [Pg.113]    [Pg.1485]    [Pg.121]    [Pg.62]    [Pg.127]    [Pg.10]    [Pg.33]    [Pg.147]    [Pg.147]    [Pg.1217]    [Pg.1111]    [Pg.551]    [Pg.1370]    [Pg.250]    [Pg.214]    [Pg.176]    [Pg.306]    [Pg.176]    [Pg.756]    [Pg.120]    [Pg.756]    [Pg.111]    [Pg.241]    [Pg.130]    [Pg.325]    [Pg.321]    [Pg.745]    [Pg.184]    [Pg.140]    [Pg.194]    [Pg.42]    [Pg.1076]    [Pg.334]    [Pg.173]    [Pg.221]    [Pg.345]    [Pg.116]   
See also in sourсe #XX -- [ Pg.308 , Pg.313 ]




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