Amines/amides Flashcards
What 2 things can amine be?
Bases (accept H+)
Nucleophile (can donate a lone pair)
What intermolecular forces within themselves do primary amines have?
Hydrogen
What intermolecular forces within themselves do secondary amines have?
Hydrogen
What intermolecular forces within themselves do tertiary amines have?
PDPD
Which one out of primary, secondary and tertiary amines is the most soluble?
Tertiary
However, all form hydrogen bonds with water
What are the 3 options for naming primary amines?
N is on the end - ___yl amine
N is not on the end - ‘number’-amino ‘name of alkane’
2 Ns - ‘Number,number’-diamino ‘name of alkane’
What are the 2 options for naming secondary amines?
R groups are the same Di ‘name of alkyl’ amine
R groups are different N-‘name of short alkyl chain’ ‘name of long alkyl chain’ amine
What are the 4 options for naming tertiary amines?
All R groups are the same - Tri’name of alkyl’ amine
Longest R group is different - N,N - Di’name of short alkyl chains’ ‘name of longest alkyl chain’ amine
All R groups are different - (in alphabetical order) N-‘alkyl chain’-N-‘alkyl chain-N-‘alkyl chain’ amine
Short R group is different - N-‘short alkyl chain’ di ‘name of long alkyl chains’ amine
How do you name salts?
Name amine
Change amine to ammonium
Add the name of the negative ion
What charge does a Nitrogen have with 3 bonds?
Neutral
What charge does a Nitrogen have with 4 bonds?
+1
How can amines act as bases?
N has a lone pair of e- so can accept H+ and act as a base
What type of bond is between ammonium and the negative ion in ammonium salts?
Ionic bonds
Why do amines smell but salts don’t?
Amines are volatile while salts aren’t
How do you get rid of the smell from an amine?
Add an acid (makes a salt)
How do you get the smell back from a salt?
Add a base (it donates the H+ so acts as an acid)
What are the 2 types of amines you can make?
Aromatic amines
Aliphatic amines
What are aromatic amines?
N is directly bonded to a benzene ring
How do you make an aromatic amine?
Start with nitrobenzene, add Tin(Sn), Conc HCl and heat under reflex
What is included in the equation when making aromatic amines?
Nitrobenzene+6[H+] goes to aromatic amine+2water
What is an aliphatic amine?
N is not directly bonded to a benzene ring
How do you make an aliphatic amine?
Start with haloalkane+excess NH3 in ethanol+heat
What is made when a haloalkane and NH3 react?
A base and an acid
What type of reaction is it when a haloalkane reacts with NH3?
Substitution
What is the problem with reacting haloalkanes with NH3?
A salt can be formed
How do you solve the problem with reacting haloalkanes with NH3?
Add a base (NaOH) (Salt loses H+ and acts as an acid)
Why do we use the excess ammonia when making an amine?
Otherwise there would be further substitutions
What mechanism does an amine do?
Nucleophilic substitution (donates a pair of electrons)
What is the bond angle/shape around the N atom in an amine?
107 degrees
Pyramidal
How do you name primary amides?
Name the chain on N + ‘amide’
eg propanamide
How do you name secondary amides?
‘N’ - name chain ‘yl’ +
Name chain on N + ‘amide’
eg N - ethyl butanamide
How do you name tertiary amides?
‘N’ - name chain ‘yl’ + ‘N’ name chain ‘yl. Put in alphabetical order
Name chain on N + ‘amide’
eg N-ethyl-N-methyl pentanamide
What happens when an amine reacts with an acyl chloride?
Makes an amide
What happens when an amine reacts with an acid anhydride?
Makes an amide
And carboxylic acid / ammonium salt (if excess NH3)
What happens when an amine reacts with a carboxylic acid?
Doesn’t make an amide, but makes a salt
What happens when you add water to an acid anhydride?
Makes 2 carboxylic acids (hydrolysis reaction)
How do you make an acid anhydride?
Add 2 carboxylic acids together (condensation reaction)
What are the only amides to form peptides?
Amino acids (have COOH and NH2)
What type of reaction joins amino acids together?
Condensation
What is the isoelectric point?
The pH that forms a zwitter ion
What happens to a Zwitter ion if the solution becomes more acidic (lower pH)
O- gains a H+ to become COOH
What is a Zwitter ion?
Amino acid where the COOH has donated a H+ to the NH2
Has a COO- side and a C(N+)H3 side
What happens to a Zwitter ion if the solution becomes more alkaline (higher pH)
C(N+)H3 become CNH2
What is the definition of an alpha amino acid?
Amine group and carboxylic acid group directly bonded to the same carbon atom
What bonds do amino acids have between each other?
Ionic as become Zwitter ions
Are amino acids/Zwitter ions soluble?
Yes, form ion-dipole attractions with water
