Abstract
Reaction of 2-amino-1,3,4-thiadiazole (
1
) with chloroacetyl chloride afforded the chloroacetamide
2
which used as starting compound for the synthesis of 2-thiocyanatoacetamide
3
and
N
-(1,3,4-thiadiazol-2-yl)acetamides
5
–
9
via reaction of
1
with various reagents. Treatment of
9
with 4-(piperidin-1-yl)benzaldehyde or DMF-DMA afforded the arylidenes
10
and
11
, respectively. Cyclization of the later compound with hydrazine hydrate gave the pyrazole derivative
12
. Furthermore, coupling of
9
with 4,6-dimethyl-1
H
-pyrazolo[3,4-
b
]pyridin-3-diazonium chloride afforded hydrazone derivative
13
, which cyclized in acetic acid to afford 1,2,4-triazine derivative
14
. Moreover, 1,3,4-thiadiazoles
15
,
19
,
22
, and
23
were achieved via reaction of
1
with different nucleophiles. Finally, 1-phenyl-1
H
-pyrazol-5(4
H
)-one when subjected to react either with
15
or with diazonium salt of
1
afforded pyrazole derivative
16
or
bis
-1,3,4-thiadiazole derivative
18
, respectively. Some of these compounds were screened for their cytotoxicity and antioxidant activities which showed promising results.
Graphical Abstract
In an effort to establish new candidates with improved activities, we reported herein the synthesis and antitumor and antioxidant evaluation of various series of
N
-substituted-2-amino-1,3,4-thiadiazoles. Newly synthesized compounds were characterized by (IR,
1
H NMR,
13
C NMR, high resolution mass spectra, and mass spectra). The representative compounds were evaluated as antitumor and antioxidant activities. Some of the prepared compounds exhibited promising activities.