Functional Group Chemistry 7 & 8 Flashcards
Describe amide stability
Very unreactive
More stable chemically than esters
L.P stabilised by resonance
What are the different types of amides?
Primary
Secondary
Tertiary
What are some important amides?
Paracetamol
Aspartame
Melatonin
What is the pKa of amides?
35
What are the properties of amides?
High B.Ps
Stable
What happens to B.Ps of liquids as intermolecular forces of solvent increase?
Increase
What is in amides?
H bonding
Strong dipole-dipole interactions
Describe amide structure
4 e- shared between 3 pi orbitals
N = planar = sp2
e- shared unequally = greater density in O
What does the amide have + why is it important?
Restricted rotation around amide bond
= gives rise to cis + trans orientations
How does solvents affect amides?
Rate of rotation is faster in least polar solvent
How are acid chlorides synthesised?
1
COOH + SOCl2 —-> CH3CH2CH2COOCl
What does an acid anhydride react with alcohol to form?
Ester + carboxylic acid
What does an acid anhydride react with H2O to form?
Carboxylic acid
What does an acid anhydride react with amine to form?
Amide + half of acid anhydride + 1 mole of amine
What is the equation for forming N-methylpropanamide?
Propanoic anhydride + 2 CH3NH2 —-> N-methylpropanamide + RNH3+ -OOCR
How do form an amide from an ester?
Ester + NH3 —-> Amide
How do you go from an amide to an ester?
Amide + MeOH —-> Ester
How do you form an amide from an acid?
COOH + RNH2 —-> Amide
Catalyst
What is the strongest C=O?
Acid halide
= very weak delocalisation
What is the weakest C=O?
Ester
= complete delocalisation
What reagents are used for dehydration of amides to nitriles?
SOCl2
P2O5
POCl3
What is the an acid chloride reduced to?
Amine
by LiAlh4
