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Q
1 An 'over-the-counter' analgesic called APC Tablets
contains aspirin, paracetamol and codeine. An extract of these
tablets was dissolved in toluene (methylbenzene) and filtered
to remove insoluble solids. Devise a separation scheme to
isolate all three drugs in a pure form.
A
1 The structures and p
K
a
values of the three drugs are shown
in Figure 3.20.
O
H
N
CH
3
OCH
3
COOH
O
HO
Paracetamol p
K
a
= 9
.
5
Aspirin p
K
a
= 2
.
5
CH
3
O
O
H
N
HO
H
H
CH
3
Codeine p
K
a
= 8
.
2
Figure 3.20
The structures and pK
a
values of aspirin, paracetamol and codeine.
