Abstract
On the account of the reported anticancer activity of pyrazolo[3,4-d]pyrimidines, a new series of pyrazolo[3,4-d]pyrimidine derivatives were synthesized and tested for in-vitro anticancer activity against Ehrlich Ascites Carcinoma (EAC) cell line. Moreover, one of the target products was evaluated for in-vivo radioprotective activity.
The reaction of o-aminoester
1 with benzylamine in presence of triethylorthoformate yielded the corresponding 5-benzylpyrazolopyrimidine derivative
2. The N-amino derivative
3 was used to synthesize new derivatives of pyrazolopyrimidines
4–
7. The corresponding 1,3,4-oxadiazolopyrazolopyrimidine derivatives
12 and
14 were obtained via reaction of compound
9 with reagent
10 and/or triethylorthoformate. Thiophosgenation of compound
1 furnished the corresponding 5-isothiocyanate derivative
15, which was reacted with o-phenylenediamine, thiosemicarbazide and anthranilic acid to give benzimidazolopyrazolopyrimidine,
17, pyrazolotriazolopyrimidine,
19 and pyrazolopyrimidobenzoxazine,
20 respectively. The structures of the synthesized compounds were confirmed by microanalyses, IR, NMR, and mass spectral data.
Compounds
2 and
9 showed intermediate anticancer activity compared to doxorubicin as positive control with IC50 values of 90 and 100
μg/ml, respectively. On the other hand, compound
5 showed significant radioprotective effect.
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