Module 6 Chapter 27
No description yet. This curated deck is ready for daily study.
Card preview (24)
What is an aliphatic amine
Nitrogen atom bonded to at least one straight or branched carbon chain
What is an aromatic amine
Nitrogen atom is attached to an aromatic ring. Phenylamine is the simplest aromatic
What are amines
They are compounds derived from ammonia, they have a H replaced with an alkyl group. They can be primary, secondary or tertiary amines
What are primary amines, secondary amines, tertiary amines
DRAW EACH
What are amines known for
Their pungent smells as well as their physiological effects
How are amines named
They use the suffix ‘-amine’ after the carbon chain prefix. Eg. Methylamine
When is the prefix amino used
For branched, more complex amines, primary amines at a different point on chain. Need to use number to indicate position.
What is a feature of secondary and tertiary amines
Each group from the amine group is named separately, the longer has the suffix amine
What is an example of a secondary amine and what is sometimes used as a prefix
Methylpropylamine Sometimes the prefix N is used
What is an example of a tertiary amine and what is sometimes used as a prefix
Diethylpropylamine. Sometimes the prefix ‘N,N’ is added when two or more different groups are attached
What is a feature of amines (PH)
Amines act as weak bases due to the lone pair on the N atom being able to form a dative bond with a proton
What is produced when an amine reacts with an acid
The salt that is formed is an ammonium salt
How do you prepare aliphatic amines
You warm halogenoalkanes gently in excess ammonia with an ethanol solvent. Amine is then generated from the salt.
What is the reaction between 1-chloropropane and ammonia
CH3CH2CH2Cl + NH3 —> CH3CH2CH2NH2 + HCL
Why is ethanol used instead of water in the reaction between 1 chloropropane and ammonia
As water will protonate the ammonia.
What do the products from the reaction between haloalkanes and ammonia do and how can this be controlled
They react with any of the amine produced to form amine salts. These salts can be removed by adding NaOH
Why is excess ammonia also added in the reaction between haloalkanes and ammonia
As this prevents further substitution with the amine products.
Why does further substitution take place in the reaction between haloalkanes and ammonia A
As the product contains lone pairs of electrons so it can react further with the haloalkane to form secondary amine.
How can tertiary and secondary amines form
By further substitution by keeping on reacting in with haloalkanes
What is another way in which amines can be formed
By the reaction of nitriles with either: Lithium tetrahydrdidoaluminate (LiAlH4) Alternatively hydrogen cna be used with a nickel catalyst.
What is the reaction of a nitrile with lithium tetrahydrdidoaluminate and hydrogen with a nickel catalyst
RC(triple bond)N + 4[H] —> RCH2NH2 RC(triple bond)N + 2H2 —> RCH2NH2
How are aromatic amines made
A nitrobenzene compound is made first It is then reduced to create an amino benzene Sn with 6M HCL used as a reluctant [H]
What can’t the NH2 group be introduced into the benzene directly
NH3 is a nucleophile Whereas benzene reacts with electrophiles
What is the steps for the formation of an aminobenzene
Step 1. Electrophilic substitution C6H6 + HNO3 —> C6H5NO2 + H2O Step 2. Reduction C6H5NO2 + 6[H] —> C6H5NH2 + 2H2O