LECTURE 9 (Heterocyclic compounds)

Question 1

What happens when an ammonium salt reacts with a strong base (e.g NaOH)?

Answer 1

It is converted back to the amine which is also called the free amine/free base

Question 2

What are Heterocycles?

Answer 2

Compounds that contain atoms other than carbon in the ring

Question 3

What can ammonium ions do?

Answer 3

React as acids in the presence of bases to regenerate the amines

Question 4

What are Ammonium salts?

Answer 4

Odorless, white, crystalline solids that are much more water-soluble than neutral amines because they are ionic

Question 5

If a free amine is needed, how is it regenerated from an amine salt?

Answer 5

It is regenerated from an amine salt by treatment with a base

Question 6

What are the properties of Quaternary ammonium ions?

Answer 6

• Four organic groups bonded to the nitrogen atom
• No H atom that can be removed by a base + no lone pair on nitrogen that can bond to H+ -> neither acidic or basic -> structures unaffected by changes in pH
• Salts called “quaternary ammonium salts”

Question 7

What are Alkaloids?

Answer 7

Roots, leaves and fruits of flowering plants which are a rich source of nitrogen compounds

Question 8

What are the properties of Alkaloids?

Answer 8

• Bitter-tasting
• Physiologically active
• Structurally complex
• Toxic to human beings + other animals
  (except for caffeine + nicotine)

Question 9

What is a Monosaccharide and Disaccharide?

Answer 9

Monosaccharide = cannot be split or hydrolysed into smaller carbohydrates

Disaccharide = consist of two monosaccharide units joined together

Question 10

What are Polysaccharides?

Answer 10

Carbohydrates that are naturally occurring polymers containing many monosaccharide units