Y13 Amines, amides, and amino acids/polymers/stereoisomers Flashcards
What are primary, secondary, and tertiary amines?
Primary: 1 carbon chain bonded to N
Secondary: 2 carbon chains bonded to N
Tertiary: 3 carbon chains bonded to N
When is the suffix -amine used when naming amines?
When the amine is at the end of the alkyl chain
When is the prefix x-amino- used?
When a primary amine isn’t on carbon 1
When are the prefixes di-x-amine or tri-x-amine used?
When secondary/tertiary amines contain the same alkyl group
When is the prefix N-x-amine used?
When 2 or more different alkyl groups are attached to the N (secondary/tertiary) - SHORTEST CHAIN FIRST
How can an amine behave as a base?
Lone pair of e- on N atom can be donated to H+ to form a dative covalent bond
What is formed when an amine reacts with an acid?
Alkylammonium ion
What is the salt formed when methylamine reacts with nitric acid?
CH3NH3+NO3-
What are the reagents, conditions and type of reaction for the conversion of a haloalkane to a primary aliphatic amine?
Reagents: Excess NH3, then NaOH
Conditions: Ethanol (solvent)
Type: Nucleophilic substitution
Why are ethanol and excess NH3 used when making a primary aliphatic amine?
Ethanol: Prevents any substitution reaction of the haloalkane with water
Excess NH3: Reduces further substitution of the amine group to form secondary/tertiary amines
What are the 2 steps to making a primary aliphatic amine?
- Substitution
- Neutralisation
What are the reagents, types of reaction, and conditions for each stage of preparing an aromatic amine from nitrobenzene?
Reagents:
1. Sn/conc. HCl
2. Excess NaOH
Type of reaction:
1. Reduction
2. Neutralisation
Conditions: Reflux
What reacts together to form an amide?
Acyl chloride reacts with NH3/an amine
What are the 2 ways an amide can be hydrolysed and which bond breaks?
- Reflux with aqueous acid
- Reflux with aqueous base
Bond between C=O and N breaks
What happens in acid conditions when hydrolysing an amide?
N atoms are protonated
What happens in base conditions when hydrolysing an amide?
COOH groups lose H+ to become COO- ions
What is the general formula of an alpha amino acid?
RCH(NH2)COOH
What makes an amino acid alpha?
When the COOH group and NH2 group are bonded to the same C
How are amino acids named?
COOH is the first carbon because it takes priority, x-amino is the prefix
When does the NH2 group of an amino acid act as a base?
In acid conditions - becomes NH3+Cl-
When does the COOH group of an amino acid act as an acid?
In base/alkaline conditions - becomes COO-Na+
What must an organic molecule have in order to show optical isomerism?
A chiral carbon
What is a chiral carbon?
Carbon bonded to 4 different atoms/groups
Condensation polymer definition
Monomers joined together by the elimination of a small molecule (water or HCl)
What are the 2 ways a polyester can be formed?
- 2 monomers, 1 with 2 COOH groups and 1 with 2 OH groups
- 1 monomer with a COOH group reacts with another monomer with an OH group
What do you put before the H2O that goes with a repeat unit?
(2n-1) H2O
What are the 2 ways polyamides can be formed?
- COOH with NH2
- Acyl chloride with NH2
What should you always check after drawing a polymer/repeat unit?
That the ends are DIFFERENT
Which types of polymer can undergo hydrolysis and which type can’t?
Condensation polymers can, addition polymers (alkenes) can’t
What are the 2 different conditions that can be used for polymer hydrolysis?
Acidic and alkaline
What must you remember when drawing monomers after a polymer has undergone acidic/alkaline hydrolysis?
Acidic: NH2 will become NH3+
Alkaline: COOH will become COO-
