6.2.1 - Amines Flashcards
How would you identify a primary amine
Nitrogen atom
1 R group attached
2 Hydrogens attached
How would you identify a secondary amine
Nitrogen atom
2 R groups attached
1 Hydrogen attached
How would you identify a tertiary amine
Nitrogen atom
3 R groups attached
How would you identify a quaternary amine
Nitrogen (+ ion)
4 R groups so 4 bonds
What are non aromatic amines
Aliphatic amines so straight chain and not in a benzene ring
What do amines usually act as ?
They usually act as bases. Since they have a lone pair on of electrons that allows them to accept a proton.
Via which type of bonding does protons bond to amines ?
Dative covalent.
Nitrogen’s lone pairs are donated to form a dative covalent.
Amines act as bases, so what does the strength of an amines as a base depend on ?
- The strengthen of the base is dependant on the availability of the lone pair of electrons on the nitrogen.
- Electron density in simple terms is how concentrated an atom is with an electrons. Basically the a cloud of a electron. Higher electron density increases your probability of finding an electron.
- Therefore the higher electron density on the nitrogen atom the more readily available the electrons are. Therefore they would bond to a proton more readily increasing the strength of the base. Vice Versa
What is the electron density on the nitrogen dependant on ?
The type of group attached to the nitrogen.
Aykl groups are electron donating increasing the electron density of the nitrogen
What do you know about naming amines general
What do you know about naming secondary amines
What do you know about tertiary alcohols
What happens when there are two groups including an amino acid
Best way to learn is to practice !
What happens when ammonia reacts with a haloalkane ?
- Use Chloroethane as an example
- React a halogenoalkane with excess ammonia.
- Rember 2 molecules of NH3 are required.
- To get your product replace the Cl on the haloalkane with NH2 (this will be your salt) and you will also form ammonium chloride (NH4 Cl)
How can primary amines react further ?
If there is excess haloalkane the primary amine can react further to secondary, tertiary amines and quaternary ammonium salt.
Write down the reaction of methyl chloride and ammonia in excess methyl chloride
Write down the reaction of ethyl chloride and ammonia in excess ethyl chloride
Why is ethanol used as a solvent in amine reactions with haloalkanes?
Ethanol prevents haloalkanes from reacting with water to form alcohols.
Why is excess ammonia used?
Excess ammonia minimizes further substitution of the amine group, reducing the formation of secondary and tertiary amines.
Reaction of quaternary ammonium salt with sodium hydroxide. Use the example Dipropylammonium chloride. Include its initial formation as well.
Why can primary, secondary and tertiary amines undergo further substitution ?
As there is still a lone pair of electrons on the nitrogen of primary, secondary and tertiary amines because the nitrogen atom still has a lone pair of electrons available for bonding. In quaternary ammonium salts, the nitrogen atom has already formed four bonds, so its lone pair is used in the dative covalent bond and is no longer available for further reactions.
Use of aromatic amines ?
Dyes and pharmaceuticals
How can we form an aromatic amine ? And draw the mechanismish
By reducing a nitrobenzene, heating it under reflux
Detail understanding of the reaction of nitrobenzene into phenylamine
