Buscar
Estás en modo de exploración. debe iniciar sesión para usar MEMORY

   Inicia sesión para empezar

level: level 4

Questions and Answers List

level questions: level 4

QuestionAnswer
where do we find the maximum electron density in aniiline resonance hybridthe NH2 group is ortho and para directing and a powerful activating group
brominationaniline reacts with bromine water at room temp. to give a white precipitate of 2,4,6-tribromoaniline
if we have to prepare monosubstituded aniline derivative how can the activating effect of -NH2 group be controlledby protecting the -NH2 group by acetylation with acetic anhydride
nitration of anilineit yields tarry oxidation products in addition to nitro derivatives in t eh presence of H2SO4
what happens to aniline in strongly acidic mediumit is protonated to form the anilinium ion which is meta directing
how can nitration reaction be controlled and p-nitro derivative can be obtained as the major productsby protecting the NH2 group by acetylation reaction with acetic anhydride
sulphonationaniline reacts with concentrated sulphuric acid to form anilium hydrogen sulphate which on heating with sulphuric acid produces p-aminobenzene sulphonic acid
common name of p-aminobenzene sulphonic acidsulphanilic acid
aniline does not undergo friedel-craft reactiondue to the formation with aluminium chloride, the lewis acid, which is a catalyst. due to this, nitorgen of aniline acquires positive charge and hence acts as a strong deactivating group for further reaction
how is benzenediazonium chloride preparedby reaction of aniline with nitrous acid and HCl
diazotisationthe conversion of primary aromatic amines into diazonium salts. due to its instability the diazonium salt is not generally stored and is used immediately after it's preparation
physical properties of benzenediazonium chloridecolourless crystalline solid. readily soluble in water and is stable in cold but reacts with water when warmed. -decomposes easily in the dry state -benzene diazonium fluoroborate is water-insoluble and stable at room temp.
reaction involving displacement of nitrogendiazonium group being a very good leaving group is substituted by Cl,Br, I, CN, and O.
replacement by halide or cyanide ion/ sandmeyer's reactionthese nucleophiles can easily be introduced in the benzene ring in the presence of Cu ion
gatterman reactionchlorine or bromine can also be introduced in the benzene ring by treating the diazonium salt solution with corresponding halogen acid in the presence of cu powder
where is the yeild better in the reaction involving displacement of nitrogensandmeyer reaction
reactions involving retention of diazo group coupling reactionbenzene diazonium chloride reacts with phenol in which the phenol molecule at it's para position is coupled with the diazonium salt to form p-hydroxyazobenzene.
importance of diazonium salts in synthesis of aromatic compoundsaryl florides and iodides cannot be formed by direct halogenation. the cyano group cannot be introduced by nucleophilic substitution of chlorine in chlorobenzene but cyanobenzene can easily be obtained from diazonium salts