When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Benzene - Wikipedia

    en.wikipedia.org/wiki/Benzene

    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]

  3. Electrophilic aromatic directing groups - Wikipedia

    en.wikipedia.org/wiki/Electrophilic_aromatic...

    However, another effect that plays a role is the +M effect which adds electron density back into the benzene ring (thus having the opposite effect of the -I effect but by a different mechanism). This is called the mesomeric effect (hence +M) and the result for fluorine is that the +M effect approximately cancels out the -I effect.

  4. Dow process (phenol) - Wikipedia

    en.wikipedia.org/wiki/Dow_process_(phenol)

    When 1-[14 C]-1-chlorobenzene was subjected to aqueous NaOH at 395 °C, ipso substitution product 1-[14 C]-phenol was formed in 54% yield, while cine substitution product 2-[14 C]-phenol was formed in 43% yield, indicating that an elimination-addition (benzyne) mechanism is predominant, with perhaps a small amount of product from addition ...

  5. Friedel–Crafts reaction - Wikipedia

    en.wikipedia.org/wiki/Friedel–Crafts_reaction

    Thus, synthesis of benzaldehyde through the Friedel–Crafts pathway requires that formyl chloride be synthesized in situ. This is accomplished by the Gattermann-Koch reaction , accomplished by treating benzene with carbon monoxide and hydrogen chloride under high pressure, catalyzed by a mixture of aluminium chloride and cuprous chloride .

  6. Substitution reaction - Wikipedia

    en.wikipedia.org/wiki/Substitution_reaction

    Nucleophilic substitutions can proceed by two different mechanisms, unimolecular nucleophilic substitution (S N 1) and bimolecular nucleophilic substitution (S N 2). The two reactions are named according tho their rate law, with S N 1 having a first-order rate law, and S N 2 having a second-order. [2] S N 1 reaction mechanism occurring through ...

  7. Arene substitution pattern - Wikipedia

    en.wikipedia.org/wiki/Arene_substitution_pattern

    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.

  8. Free-radical addition - Wikipedia

    en.wikipedia.org/wiki/Free-radical_addition

    In organic chemistry, free-radical addition is an addition reaction which involves free radicals.These reactions can happen due to the free radicals having an unpaired electron in their valence shell, making them highly reactive.

  9. Cumene process - Wikipedia

    en.wikipedia.org/wiki/Cumene_process

    The cumene process (cumene-phenol process, Hock process) is an industrial process for synthesizing phenol and acetone from benzene and propylene. The term stems from cumene (isopropyl benzene), the intermediate material during the process. It was invented by R. Ūdris and P. Sergeyev in 1942 (USSR), [1] and independently by Heinrich Hock in ...