Synthesis of Some Pyrazolo[3, 4]pyrimidine Derivatives for Biological Evaluation

Abstract

A novel β -enaminonitrile of 1-(6-p-tolyl-pyridazin-3-yl)-pyrazole derivative 2 was formed using (6-p-tolyl-pyridazin-3-yl)-hydrazine ( 1 ) and 2-ethoxymethylenemalononitrile. The β-enaminonitrile derivative 2 was in turn used as a precursor for the preparation of pyrazoles ( 4 , 6 ), pyrazolo[3, 4-d]-pyrimidines ( 3 , 7–12 ) and pyrazolo[4, 3-e][1,2,4]triazolo[4,3-c]pyrimidine ( 13 ). Also, N- and S-acyclic nucleosides 14 and 15 were prepared. Some of the prepared products showed potent antimicrobial activity.

Keywords:

• β-enaminonitrile
• acyclic nucleosides
• pyrazole
• pyrazolo[3,4-d]pyrimidine
• pyrazolo-[4,3-e]-[1,2,4]triazolo[4,3-c]
• pyrimidine

We are thankful for Dr. H. M. Awad, Department of Natural and Microbial Products, National Research Centre, for his biological evaluation.

Notes

+++ Highly sensitive (inhibition zone = 21–25 mm).

++ Fairly sensitive (inhibition zone = 16–20 mm).

+ Slightly sensitive (inhibition zone = 10–15 mm).

– No sensitivity.