Chemistry of 4,4′‐(arylmethylene)‐bis(3‐methyl‐1‐phenyl‐1H‐pyrazol‐5‐ol)s

Abstract

This review presents a systematic and comprehensive survey of the method of preparation and the chemical reactivity of 4,4′‐(arylmethylene)‐bis(3‐methyl‐1‐phenyl‐1H‐pyrazol‐5‐ol)s. The target compounds are important intermediates for the synthesis of a variety of synthetically useful and novel heterocyclic systems.

New 1,2,3-Triazole-Appended Bis-pyrazoles: Synthesis, Bioevaluation, and Molecular Docking

“…Several researchers have paid attention toward the synthesis of bis-pyrazole molecules 17 because of their diverse biological activities; the representative structures of the molecules 1−7 are shown in Figure 1. Sujatha and co-workers reported 18 the facile synthesis of bis-pyrazoles 1 and evaluated their in vitro antiviral activity.…”

Greener Synthetic Approach for 4,4′‐(Arylmethylene)bis(3‐methyl‐1H‐pyrazol‐5‐ol) Derivatives in an Aqueous Medium using Theophylline as a Catalyst

“…Literature survey shows that the most common method for the synthesis of 4,4'-(phenylmethylene) bis(3-methyl-1-phenyl-1H-pyrazol-5-ol) is the condensation of aldehydes with 3methyl-1-phenyl-5-pyrazolone. Several catalysts have been used for this reaction including Mohr's Salt, [25] Ni-guanidine@MCM-41 NPs, [26] PEG-400, [27] silica sulfuric acid, [28] sulfonated rice husk ash (RHA-SO 3 H), [29] sulfuric acid ([3-(3silicapropyl)sulfanyl]propyl)ester, [30] tetrakis(N-methylimidazolium-1-ylmethyl)methane tetra hydrogen sulfates, [31] Xanthan sulfuric acid, [32] [Et 3 NH][HSO 4 ], [33] 1-(carboxymethyl)pyridinium chloride {[cmpy]Cl}, [34] Na + -MMT-[pmim]HSO 4 , [35] cage like CuFe 2 O 4 hollow nanostructure, [36] Chitosan-SO 3 H (CTSA), [37] DCDBTSD, [38] guanidine hydrochloride, [39] lemon juice, [40] Mn-lysine complex on magnetic nanoparticles, [41] NPS-γ-Fe 2 O 3 , [42] SDBS, [43] K 2 CO 3 , [44] Pyridine trifluoroacetate, [45] Phosphomolybdic acid, [46] L-Proline, [47] Cu-ZnO, [48] ChCl:TA, [49] chickpea leaf exudates (CLE), [50] ZnO NPs, [51] and BPHCSF [52] However, most of these synthetic methods display some disadvantages such as employing strong acidic conditions, toxic reagents, expensive catalysts, tedious workup procedures, harsh reaction conditions, and low yields of the products that restrict their usage in practical applications. Considering these lacunas with already reported synthetic protocols, there is still scope for designing a suitable synthetic protocol, which is environmentally benign.…”

Evaluation of the Anti-Leishmania mexicana and -Trypanosoma brucei Activity and Mode of Action of 4,4′-(Arylmethylene)bis(3-methyl-1-phenyl-1H-pyrazol-5-ol)

“…The conventional methods for the synthesis of 4,4′-(arylmethylene)bis(1 H -pyrazol-5-ols) 2 consist of a Michael addition of an aromatic aldehyde 3 to an arylidenepyrazolone, which is obtained via the Knoevenagel reaction. These reactions can be performed separately [ 27 , 28 ] or in one step, either via the reaction of pseudo-five [ 29 , 30 ] or pseudo-three components, and use a wide variety of catalysts [ 31 ].…”