Chemistry Reference
In-Depth Information
Ansari
et al.
[32a] have developed a microwave synthesis of a 33-membered library of 3-hydroxychalcones by
reaction of 3-hydroxyacetophenone with different substituted aryl- and heteroaryl aldehydes under Claisen-Schimidt
conditions (Fig.
15
). The reaction time under microwave irradiation had a significant decrease when compared with
classical conditions, ranging from 30 seconds to 3 minutes (first method) and from 3 to 5 hours (last method) [32b].
The synthesized chalcones showed potential antibacterial activity, against
B. bronchiseptica
respiratory tract
infections.
A series of novel polycyclic-fused isoxazolo[5,4-
b
]pyridines was efficiently synthesized (one pot) under microwave
irradiation in water. Isoxazole has been widely used as a key building block for lead compounds which are
biologically active.
Its derivatives have diversified pharmacological properties, such as analgesic, anti-inflammatory, anti-HIV,
hypoglycemic, anticancer and antibacterial activity (Fig.
16
) [33].
Many 2-pyridone and 2-quinilone analogs display antiulcer, antifungal and antiphlogistic properties and even, some
representatives are described as specific non-nucleoside reverse transcriptase inhibitors of human immunodeficiency
virus-1 (HIV-1) [34,35].
Ar
CH
3
O
O
N
O
CH
3
N
O
H
2
O, MW
ArCHO
H
2
N
Ar
O
CH
3
O
O
H
2
O, MW
O
N
O
O
N
isoxazolo[5,4-b]pyridines derivatives
F
OMe
OMe
OMe
OMe
MeO
OMe
CH
3
CH
3
CH
3
CH
3
O
O
O
O
N
N
N
N
O
O
O
O
N
N
N
N
OH
F
OMe
NO
2
NO
2
OMe
CH
3
CH
3
O
O
CH
3
CH
3
O
O
N
N
O
N
O
N
O
O
N
N
O
O
N
N
OMe
OMe
OH
MeO
OMe
NO
2
NO
2
CH
3
CH
3
CH
3
CH
3
O
O
O
O
N
O
N
O
N
N
Figure 16:
Polycyclic-fused isoxazolo[5,4-
b
]pyridines derivatives synthesized under microwave irradiation in water.
O
O
O
O
N
N
N
N
