Study on One‐pot Biginelli‐like Synthesis of Pyrazolo[3,4‐d]pyrimidines in Bronsted Acidic Ionic Liquid Under Sonication and its Mechanism

Synthesis, identification and in vitro biological evaluation of some novel 5-imidazopyrazole incorporated pyrazoline and isoxazoline derivatives

“…Many pyrazoline derivatives are reported to have a large spectrum of biological activities, such as antimalarial, 24 antibacterial, 25 antitubercular, analgesic, 26 antiviral, 27 antioxidant, 28 antidiabetic, 29 antifungal 30,31 and antimycobacterial. 32 In view of these findings and in continuation of our research work, [33][34][35][36][37][38][39][40][41] we herein report the synthesis and pharmacological activity of substituted pyrazolines 6a-l and isoxazolines 7a-l. It was considered valuable to incorporate two five membered heterocyclic rings mutually in a molecular framework to study the synergistic effect of these rings towards the antibacterial, antituberculosis, antimalarial and antioxidant activities (Fig.…”

Efficient Green Protocols for the Preparation of Pyrazolopyrimidines

“…They have many applications in synthetic chemistry such as reducing reaction time, reaction temperature as well as the amount of reaction intermediate formed to provide a better yield than the conventional methods. [76,77] So nowadays, sonochemistry can be applied in various areas like organometallic chemistry, heterogeneous metal-catalyzed reactions, and, also in phase transfer catalysis reactions. [78] Pyrazolopyrimidine is an important chemical moiety to develop potential chemotherapeutics agents.…”

“…[92] A simplistic and green one-pot synthetic protocol for preparation of 1H-pyrazolo [3,4-d]pyrimidine from various aromatic aldehydes, 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3one and thiourea or urea in ionic liquid with Bronsted acidic properties, 1-butyl-1H-imidazol-1-ium tetrafluoroborate ([HBim] BF 4 ) under ultrasound irradiation at ambient reaction condition was reported by Thummar et al The method provides the advantage of easy preparation, mild reaction conditions, easy isolation of product, higher yields and recyclability of ionic liquid (Scheme 63). [76] Mechanism: The multicomponent reaction involves the formation of an adduct via Knoevenagel condensation of aromatic aldehydes with 5-methyl-2-phenyl-2,4-dihydro-3Hpyrazol-3-one. Further Michael addition of urea or thiourea takes place with subsequent intramolecular cyclization and then removal of a water molecule to finally provides the derivatives of 1H-pyrazolo [3,4-d]pyrimidine (Figure 16).…”

Green synthesis and pharmacological screening of polyhydroquinoline derivatives bearing a fluorinated 5-aryloxypyrazole nucleus

“…In continuation of our efforts to synthesize some novel heterocyclic motifs with biological interest, [30][31][32][33][34][35][36][37] herein we report for the synthesis and biological screening of novel polyhydroquinoline derivatives bearing a uorinated 5-aryloxypyrazole nucleus using ultrasonic irradiation. In the context of biological importance, we intended to develop novel approach for structural diversity of heterocycles incorporating polyhydroquinoline scaffold.…”