Novel synthesis of highly functionalized pyrazolone systems via rearrangement of 5-phenyl-1-oxa-5,6-diazaspiro[2.4]heptane-4,7-diones

Catalytic and Multicomponent Reactions for Green Synthesis of Some Pyrazolone Compounds and Evaluation as Antimicrobial Agents

“…The formation of 24 may involve the nucleophilic ring opening of the oxirane ring through the attack of ammonia to produce the intermediate ( 22 ), which will be hydrolyzed to generate the 4-aminopyrazole intermediate ( 23 ), followed by air oxidation to produce the pyrazolone derivative ( 24 ) (Scheme ). Moreover, 18 reacted with phenylhydrazine and/or 4-methoxyphenylhydrazine ( 25a, b ) and imidazole ( 3 ) (0.5 mmol) to give the pyrazole-4-carboxylic acid derivatives ( 27a,b ). , Such a ring transformation reaction may take place via the plausible nonisolated intermediates, as shown in the following suggested reaction mechanism (Scheme ).…”

“…Moreover, 18 reacted with phenylhydrazine and/or 4-methoxyphenylhydrazine ( 25a, b ) and imidazole ( 3 ) (0.5 mmol) to give the pyrazole-4-carboxylic acid derivatives ( 27a,b ). 42 , 43 Such a ring transformation reaction may take place via the plausible nonisolated intermediates, as shown in the following suggested reaction mechanism ( Scheme 9 ).…”

“…Therefore, one of the study topics of chemists is the synthesis of novel molecules having antimicrobial characteristics. − Pyrazolone derivatives are considered essential components in antimicrobial drug discovery . Throughout the continuation of our attempts is toward the methodologies for an ecofriendly synthetic facility with the significant benefits of rate acceleration in water as the reaction medium and utilizing a MCR approach. − The simple and practical water-assisted MCR method for the production of pyrazolone derivatives with the benefit of green chemistry and the expectation that they will have interesting biological activity applications is described.…”

The Reaction of 1‐Phenylpyrazolidine‐3,5‐dione with Active Nitriles Using Phase Transfer Catalysis Conditions Technique

“…Pyranopyrazoles, 1,3‐thiazines, thiazoles , thienopyrazoles , and furopyrazole represent important classes of heterocycles, which have been developed for different purposes in the pharmaceutical field. In continuation of our previous works, which had dealt with using active nitriles in synthesis of polyfused‐ and spiropyrazoles, herein, we report the synthesis of pyrano[2,3‐ c ]pyrazole, thiazole, 1,3‐thiazine, 1,3‐oxothiinopyrazole, and furo[2,3‐ c ]pyrazole derivatives starting with 1‐phenylpyrazolidine‐3,5‐dione.…”

“…3,5‐Pyrazolidendiones were reported to possess antibacterial, anti‐inflammatory, antiviral, antimicrobial and uricosuria properties. Pyranopyrazoles, 1,3‐thiazines, thiazoles , thienopyrazoles , and furopyrazole represent important classes of heterocycles, which have been developed for different purposes in the pharmaceutical field.…”