1. 8-aminoquinolines
• Drugs in this group have amino group at
position 8 of quinoline ring
• Important members of this
family include
1- Pamaquine
2- Primaquine, etc.

2. • Such drugs have OCH3 group at position 6
• This molecule has antimalarial
activity but when side chain
is introduced at amino
group antimalarial activity is
intensified e.g
pamaquine
• It causes hemolysis
of RBCs
Diethyl amino pentyl side chain

3. • It contains tertiary amino group and when it is
converted into primary amino group the
compound is called primaquine, which is
– Less toxic
– Well tolerated
– It is the most commonly used agent in this group
in the treatment of malaria

4. • OCH3 is not necessary for antimalarial activity
but when replaced by OC2H5 the compound
became
– less active
– Toxic in nature
• OCH3 when replaced by CH3 the compound
become inactive
• Introduction of halogens increases toxicity
• Presence of quinoline ring is necessary for
antimalarial activity. When pyridine ring is
converted to piperidine (saturated) the
compound became inactive

5. • Pentyl side chain gives maximum activity,
increase or decrease of chain result is reduction
of activity.
• The branched side chain when converted into
straight chain pentaquine is obtained
• It has less antimalarial activity as compared to
both pamaquine and primaquine

6. Chemical synthesis (pamaquine)
• Glycerol undergoes dehydration to produce
propene aldehyde
• Dehydrating agent is sulphuric acid

7. • Addition reaction of propene aldehyde and 4
methoxy 2-nitro aniline to form 4 methoxy 2-
nitro propene aldehyde

8. • Tautomerization: 4 methoxy 2-nitro propene
aldehyde (keto form) converted in enol form

9. • Enol form undergoes cyclization to form 8 nitro 6
methoxy dihydroquinoline which then oxidized to
form 8 nitro 6 methoxy quinoline

10. • 6 methoxy 8 nitro quinoline undergoes
reduction to form 8 amino 6 methoxy
quinoline

11. • 8 amino 6 methoxy quinoline reacts with 2
chloro diethyl amino pentane to form
pamaquine

12. Therapeutic uses
• Active against hepatic stage of plasmodium
• Provide radical cure hepatic stage of P. vivax
and P. ovale
• It also acts at gametocytes, hence used as
prophylactic drugs
• Used in combination with chloroquine for
complete eradication of malaria
• Side effect: hemolysis in G6 phosphate
dehydrogenase deficient people