Nitroglycerin--a cardiac drug
CH2-O-NO2
l
CH2-O-NO2
l
CH2-O-NO2
3-16. AMIDES
Amides are formed from the reaction of a carboxylic acid with an amine or
ammonia and have the general formula
O
where R and R' can be the same
or different hydrocarbon groups.
R-C-NH-R'
a. Properties of Amides. Amides, because of the hydrogen attached to the
boiling and melting points than corresponding alkanes. Since they can also form
hydrogen bonds with water, amides containing up to five carbon atoms are soluble in
water.
b. Reactions of Amides. Amides are neutral in pH and undergo the
hydrolysis reaction. For amides, hydrolysis is the splitting of the compound with the
incorporation of water to form a carboxylic acid and an amine.
O
O
ll
ll
R-C-O-NHR' ------> R-C-OH + R'-NH2
H2O
c. Uses of Amides. Some examples of drug molecules containing the amide
functional group are shown below1
CH3
O
C2H5
Lidocaine (Xylocaine) = local
ll
anesthetic
О
NH-C-CH2-N
CH3
C2H5
Dibucaine (Nupercaine) = local
anesthetic
Ο
O H
ll ll
C2H5
N
C-N-CH2-CH2-N
C2H5
O-C4H9
3-17
MD0803