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Chapter 19 659
Copyright © 2017 Pearson Education, Inc.
19.
N
N
H N
N
OH
H
2
N
enol form of guanine
N
N
NH
2
HO
enol form of cytosine
20.
The second nitrogen in protonated pyrimidine (that withdraws electrons inductively) causes it to be a
stronger acid than protonated pyridine.
p
K
a
=
1.0
p
K
a
=
5.2
protonated pyrimidine
protonated pyridine
N
H
+
N
N
H
+
21.
a.
2-methylazacyclobutane or 2-methylazetidine
b.
2,3-dimethylazacyclohexane or 2,3-dimethylpiperidine
c.
3-chloropyrrole
d.
2-ethyl-5-methylazacyclohexane or 2-ethyl-5-methylpiperidine
22.
a.
N
C
O
b.
N
H
O
c.
CH
3
CH
2
CH
2
CH
2
CH
2
NH
2
d.
O
CH
3
C
CH
3
O
e.
N
f.
NH
2
CH
2
CH
2
CH
3
+
Br
−
g.
N
H
NN
h.
N CH
2
CH
2
CH
2
CH
3
i.
S COOH