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This category includes chemical compounds that are derivatives or structural analogs of benzene in which the benzene has multiple substituents or bonds. For benzene derivatives that include a phenyl group, C 6 H 5 – (benzene with only one substituent or bond), see the child category, Category:Phenyl compounds.
Because inductive effects depends strongly on proximity, the meta and ortho positions of fluorobenzene are considerably less reactive than benzene. Thus, electrophilic aromatic substitution on fluorobenzene is strongly para selective. This -I and +M effect is true for all halides - there is some electron withdrawing and donating character of each.
Benzene is sufficiently nucleophilic that it undergoes substitution by acylium ions and alkyl carbocations to give substituted derivatives. Electrophilic aromatic substitution of benzene. The most widely practiced example of this reaction is the ethylation of benzene. Approximately 24,700,000 tons were produced in 1999. [73]
Alkylbenzenes are derivatives of benzene, in which one or more hydrogen atoms are replaced by alkyl groups. The simplest member, toluene (or methylbenzene), has the hydrogen atom of the benzene ring replaced by a methyl group. The chemical formula of alkylbenzenes is C n H 2n-6. [2] Safety hazards of toluene.
The equation also holds for reaction rates k of a series of reactions with substituted benzene derivatives: log k k 0 = σ ρ {\displaystyle \log {\frac {k}{k_{0}}}=\sigma \rho } In this equation k 0 {\displaystyle {k}_{0}} is the reference reaction rate of the unsubstituted reactant, and k that of a substituted reactant.
In the petroleum refining and petrochemical industries, the initialism BTX refers to mixtures of benzene, toluene, and the three xylene isomers, all of which are aromatic hydrocarbons. The xylene isomers are distinguished by the designations ortho – (or o –), meta – (or m –), and para – (or p –) as indicated in the adjacent diagram.
In organic chemistry, dihydroxybenzenes (benzenediols) are organic compounds in which two hydroxyl groups (−OH) are substituted onto a benzene ring (C 6 H 6).These aromatic compounds are classed as phenols.
In meta-substitution, the substituents occupy positions 1 and 3 (corresponding to R and meta in the diagram). In para-substitution, the substituents occupy the opposite ends (positions 1 and 4, corresponding to R and para in the diagram). The toluidines serve as an example for these three types of substitution.