6.2.1 - Amines Flashcards
What is an amine?
Derivatives of ammonia where one or more of the hydrogen atoms has been replaced by an alkyl or aryl group.
What is a NH2 group?
Amino.
What do amines act as?
Weak bases.
Write an equation for when amine acts as a base?
NH3 + H+ -> NH4+
How does an amine act as a base?
The nitrogen atom accepts a proton by using its lone pair of electrons which can be donated to the proton forming a dative covalent bond.
What do amines form when they react with acids?
Salts
CH3CH2NH2 + HCl ->
CH3CH2NH3+Cl-
Ethylamine and sulphuric acid?
2CH3CH2NH2 + H2SO4 -> (CH3CH2NH3+)2 SO42-
What is an aliphatic compound?
A hydrocarbon group with the carbons joined in a chain or non-aromatic rings.
What are the reagents and conditions for the preparation of aliphatic amines?
A haloalkane with excess ethanoic ammonia, heat in a sealed tube.
Why must the reagents be heated in a sealed tube?
Ammonia is too volatile to be refluxed.
What is ethanoic ammonia?
Ammonia dissolved in ethanol.
What is the equation for the production of propylamine from propylchloride?
CH3CH2CH2Cl + 2NH3 -> CH3CH2CH2NH2 + NH4Cl
What is the problem with the use of a haloalkane to produce an amine?
It is difficult to stop the reaction at the primary amine and so this can go on to form secondary and tertiary amines. Excess ammonia is used to minimise this.
How can secondary amines be formed?
Ammonia, primary amine and another haloalkane.
What is the benefit of using RCN to produce amines?
They only produce the primary amine.
What does aromatic mean?
Contains a benzene ring.
What are the reagents and conditions for the preparation of aromatic amines?
Nitrobenzene with tin and concentrated HCl (reducing agent). Heat under reflux, followed by neutralisation with NaOH.
Equation for the production of phenyl amine?
C6H5NO2 + 6[H] -> C6H5NH2 + 2H20
Phenyl amine + HCl
C6H5NH3Cl
C6H5NH3Cl + NaOH
C6H5NH2 + NaCl + H2O
