18b - amines, amides & amino acids Flashcards
how could amines act as bases?
lone pair of e- on N readily available to form dative covalent bond with H+
which is a stronger base, NH3 or amines? why?
amines
alkyl groups are e- releasing & pushes e- towards N atom & makes it a stronger base
does phenylamines form basic solutions? why?
no
lone pair of e- on N is delocalised with e- ring
-> less able to accept protons
how could amines form complex ions?
lone pair of e- on N enable amines to act as ligands
how could primary amines be formed from halogenoalkanes?
one-step nucleophilic substitution
why is using halogenoalkanes not a great method to make amines?
lone pair still available on N - further substitution -> low yield
how could primary amines be prepared from nitriles?
1- convert halogenoalkane to nitrile
reagent- ethanol & KCN
conditions - heat under reflux
2- reduce nitrile to amine
reagent- LiAlH4 in dry ether
what are nitroarenes?
benzene with NO2 group
how are aromatic amines formed from nitroarenes?
reagent- Sn & HCl
conditions - heat
mechanism - reduction
what does grignard reagents do?
increase carbon chain length
how are grignard reagents made?
halogenoalkane dissolved in dry ether & reacted with Mg
which is the nucleophile in the grignard reagent?
alkyl group since it’s negative
what does grignard reagent & methanal form?
primary alcohol
what does grignard reagent & aldehyde form?
secondary alcohol
what does grignard reagent & carbon dioxide form?
carboxylic acid
