Basic retrosynthetic approaches in drug synthesis

Question 1

Synthetic step

Answer 1

• Shows how
  to convert the epoxide
  derivate into Propranolol
• Reagent react to make product such as SN2 reaction

Question 2

Retrosynthetic Analysis

Answer 2

• The synthesis was done
  from right to left drawn
  from the product to the reactant

Question 3

Concideration of retrosynthetic approach

Answer 3

• Minimise the costs and make synthesis green & max percentage yield
• Minimise single steps
• Max yeild to minimise side product

Question 4

Types of synthesis

Answer 4

• Linear synthesis
• Covergent synthesis

Question 5

Linear synthesis

Answer 5

• Progressive step to reach target molecule
• Overall yeild decreases most reagent wasted

Question 6

Convergent synthesis

Answer 6

• Sarting from two molecules then forming two products combined has a greater overall yield
• Lower steps so short amount of time
• Higher yeild and better carbon economy

Question 7

The synthon approach

Answer 7

• Target molecule break down to form synthons
• Convert the synthons to synthetic equivalent
• Electrons when bond is broken removed postive on carbon negative on nitrogen (synthon) due to electronegativity as N more electroneg

Question 8

Phenyl and carboxylic Common disconnection points

Answer 8

• C-C from the C of the phenyl ring and C of carbonyl ring
• C=O carbonyl group due to friedel crafts acytylation

Question 9

Phenyl and aliphatic chain Common disconnection points

Answer 9

• Negative charge on phenyl ring and positive on aliphatic chain
• Friedel crafts alkylation

Question 10

Common breaking points between two carbon Sp2

Answer 10

• Break between the the two phenyl groups that undergo suzuki coupling

Question 11

Common breaking points

Answer 11

• Break between the carbon nitrogen bond
• Nitrogen gets negative charge and carbon gets positive
• Nucleophilic acyl sub

Question 12

Common breaking points of C-O bond

Answer 12

• Fisher esterification react with the base and the chloride
• O attached to phenyl neg charge compare to C=O

Question 13

Common breaking points
C-N primary secondary and tertiary

Answer 13

• Alkylation of amine by alkyl halides SN2 reaction
• N has negative charge and C has positive

Question 14

Common breaking points of nucleophile

Answer 14

• Formation of epoxide at break point
• Example of propranolol

Question 15

Functional group interconversion

Answer 15

• Sacrificial group present example grignard reagent no presence of oxgen after converting to alkene

Question 16

Break down of prasugrel into 2 synthons

Answer 16

• Use the irreversible antagonist P2Y12
• Nitrogen breaking point C-N disconnection

Question 17

Prepare aspirin from phenol

Answer 17

• Break between C-O and C=O