Chemistry Reference
In-Depth Information
A third class of ACE inhibitors is represented by fosinopril sodium
(Monopril
®
, Bristol-Myers Squibb), a phosphinate ester which hydrolyzes
in vivo to the phosphinic acid.
O
O
O
P
O
O
N
CO
2
H
Fosinopril
Calcium channel blockers, also known as calcium antagonists, are a class
of hypertension drugs that inhibit the influx of calcium ions through the cell
membrane. A decrease in calcium ions results in less contraction of the car-
diac and vascular muscles. There is an increase in the diameter of the arteries.
This vasodilatation results in a lowering of the blood pressure. Despite their
name, calcium channel blockers do not “plug the hole” and physically block
the calcium ion channel. Rather, they bind to specific receptor sites [30].
Examples of calcium channel blockers are nifedipine (Procardia
®
, Pfizer),
nicardipine hydrochloride, amlodipine besylate sulfonate (Norvasc
®
, Pfizer).
and verapamil hydrochloride (Calan
®
, Pfizer). Verapamil has a chiral carbon
but is administered as a racemic mixture.
Cl
O
2
N
SO
3
H
CO
2
CH
3
CO
2
CH
3
H
3
CO
2
C
H
3
CO
2
C
H
3
C
O
H
3
C
H
CH
3
H
NH
2
Nifedipine
Amlodipine besylate
O
2
N
CH
3
O
N
CH
3
CN
H
3
CO
OCH
3
O
N
H
3
CO
2
C
HCl
HCl
H
3
C
H
CH
3
H
3
CO
OCH
3
Nicardipine hydrochloride
Verapamil hydrochloride
Nifedipine can be made by a Hantzsch synthesis in a one-step convergent
synthesis. However, the product purity is problematic and it is better to syn-
thesize nifedipine in a series of steps [31].
Search WWH ::
Custom Search