Pyrazolo[1,5‐a]Pyrimidine Derivative as Precursor for Some Novel Pyrazolo[1,5‐a]Pyrimidines and Tetraheterocyclic Compounds

Abstract

The 2‐(cyanomethyl)‐5,7‐dimethylpyrazolo[1,5‐a]pyrimidine‐3‐carbonitrile 3 reacted with phenyl isothiocyanate to afford the respective thioanilide derivative 4 that is a novel compound that has been unreported hitherto. The latter was used as a precursor to synthesize several novel polyheterocyclic compounds 9, 12, 15, and 19. Treatment of the enamine derivative of compound 3 with each of hydrazine hydrate and hydroxylamine hydrochloride yielded the tetraheterocyclic compounds 22 and 23, respectively. The structures of all the newly synthesized compounds were confirmed on basis of their elemental, spectral data, and plausible mechanism has been postulated to account for their formation. X‐ray crystallography was carried out as a further evidence for the structure of the isolated product 19.

Synthesis of some novel N5‐sulfonylated and N1‐alkyated pyrazole derivatives and their antimicrobial activity in conjunction with molecular docking study

“…[14] Moreover, 5-amino-1H-pyrazoles considered as a starting material for building pyrazolo-fused ring systems in medicinal field, such as pyrazolopyrimidines, [15][16][17][18] pyrazolopyridines, [19] and pyrazolotriazines. [20,21] Owing to the above mention of the importance of 5-aminopyrazoles and as extension to our work to synthesize heterocyclic ring systems of interest biological activity, [22][23][24][25][26][27][28][29][30][31] we report herein the synthetic route of chemical modification of 5-aminopyrazoles, which can serve as a promising source of bioactive small molecules.…”

Novel fluorinated pyrazole-based heterocycles scaffold: cytotoxicity, in silico studies and molecular modelling targeting double mutant EGFR L858R/T790M as antiproliferative and apoptotic agents

“…Due to their broad potential biological and chemotherapeutic activities, organic chemists have been attracted by pyrazolo-pyrimidine derivatives in recent years. Pyrazolo-pyrimidine's biological activities include anxiolytic [29], tuberculostatic [30], neuroleptic [31], benzodiazepine receptor ligands [32], antimalarial, antioxidant [33], and antifungal effects [34]. Also, they appeared in many significant bioactivities such as anti-inflammatory [35], anticancer [36][37][38][39][40][41], and antimicrobial [42].…”