Iodine-Mediated Synthesis of Novel Pyrazole Derivatives

Abstract

The reaction between N,2-diarylhydrazinecarbothioamide (generated from arylhydrazines and aryl isothiocyanates) and malononitrile in the presence of iodine/triethylamine in N,N-dimethylformamide at 80 °C afforded novel pyrazoles, 5-amino-1-aryl-3-(arylamino)-1H-pyrazole-4-carbonitriles, in good yields. In this strategy, iodine served as a versatile desulfurizing agent, efficiently promoting the cyclization reaction.

Development of novel ferrocene‐based MNP and its catalytic activity investigation in the synthesis of 3‐amino benzyl‐4‐hydroxycoumarin derivatives

“…[20][21][22] Therefore, modifying magnetic nanoparticles' surface with ILs has several unique properties, including a simple synthesis route, high stability, easy separation from the reaction medium, large surface area, low toxicity, and low price. [23][24][25][26][27][28][29][30] Nowadays, a variety of catalysts have been developed and used for the synthesis of hydroxycoumarin derivatives such as [Et 3 NH] [HSO 4 ], 31 Zn 3 (PO 4 ) 2 .H 2 O, 32 {Fe 3 O 4 @Cys-SO 3 H} MNPs, 33 Fe 3 O 4 NPs, 34 [HO 3 S-PhospIL@SBA-15], 35 and {Fe 3 O 4 @-SiO 2 @Im-bisethylFc (HC 2 O 4 )}. 36 Also, Kumar et al have developed an efficient non-ionic surfactant-catalyzed multicomponent synthesis of novel Benzylamino coumarin derivatives in water.…”

Arene Binuclear Ru(II)-Promoted Sustainable Synthesis of Substituted Pyrazoles from Alcohols via Acceptorless Dehydrogenative Annulation

“…The importance of the pyrazole moieties has resulted in the establishment of multiple efficient synthetic pathways to generate their derivatives . The traditional procedures for the construction of pyrazole derivatives include the condensation reaction of substituted hydrazines with carbonyl/dicarbonyl and aryl halides, including the oxidative cyclization reaction of hydrazones catalyzed by iodine or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) . Multicomponent reactions enable the cost-effective and time-efficient production of diversified N -heterocycles from readily available precursors. , However, the above approaches have some drawbacks, such as the usage of unstable aldehyde reactants, use of expensive additives, toxicity, poor selectivity, and difficult workup process.…”