medchem 18

Question 1

does amide have low or high melting point ?

Answer 1

high due to the hydrogen bonding ( doors and acceptors ) in primary and secondary but not teitry bc it has no hydrogen bonds

Question 2

properties of amides:

Answer 2

• low reactivity
• high melting and boiling point
• the nitrogen is a very weak nulephile and base
• decreased elctrophility of carbon due to resonance
• carbon and nitrogen bonds are shorter than expected for a single bond.
• the geometry between carbon and nitrogen is troagonal planer
• the lone pairs in nitrogens are not free making the amides very weak basic
• the subutiuents in seondary and teritry amides are usually in trans configuration

Question 3

peptides/proteins are amino acids linked together by —

Answer 3

• peptide/ amide bonds

Question 4

amides bonds are unreactive towards —- which is an important factor for —-

Answer 4

• water as in nuclephile
• stability of proteins and peptides in water

Question 5

amides can be synthesisef from:

Answer 5

• ester
• acid chlorides
• acid anydhdide

Question 6

acid cholride/acid anhydride with nh3:
with rnh2:
with r2nh:

Answer 6

• primary amide
• seoncdary aminde
• tertry amide

Question 7

paracetamol is a —-

Answer 7

secondary amide

Question 8

paracetamol is synthesised from —

Answer 8

p-hydroxyanaline and acetic anhydride
so it produces paracteoml and acetic acid

Question 9

carbolyxicv acids with basic reagents as r-nh2 produces

Answer 9

carboxylate and salt so nh3-r -

Question 10

most peptides are formed by the reactions of —-

Answer 10

amines ( from amino acids ) with esters and they are the most reactive