...
5
4
3
2
1
4
4
5
3
2
1
5
3
2
1
Pyramidon
Antipyrin
1-Phenyl -2 , 3-dimethyl-4-dimethylamino-5-Pyrazolo
n
1-Phenyl -2 , 3-dimethyl-5-Pyrazolon
5-Pyrazolon
CN
N
O
CH
3
CH
3
C
6
H
5
(CH
3
)
2
N
CN
N
O
CH
3
CH
3
C
6
H
5
CN
N
H
O
Khung ...
3
11
2
N
N
H
N
N
H
1,3-Diazol
1 , 2- Diazol
3
2
1
1
N
S
N
S
1,3-Thiazol
1 , 2- Thiazol
1
N
O
N
O
1,3-oxazol1 , 2- oxazol
1
2
3
Dị vòng 3...