Pyrazolone

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Yi Pan - One of the best experts on this subject based on the ideXlab platform.

Rui Wang - One of the best experts on this subject based on the ideXlab platform.

Chen Xie - One of the best experts on this subject based on the ideXlab platform.

Lipeng Zhang - One of the best experts on this subject based on the ideXlab platform.

  • One-pot Synthesis of Pyrazolone Sulfones by Iodine-catalyzed Sulfenylation of Pyrazolones with Aryl Sulfonyl Hydrazides Followed by Oxidation in Water
    Current Organic Synthesis, 2018
    Co-Authors: Xia Zhao, Lipeng Zhang
    Abstract:

    Aim and Objective: Pyrazolone sulfones have been reported to exhibit herbicidal and antibacterial activities. In spite of their good bioactivities, only a few methods have been developed to prepare Pyrazolone sulfones. However, the substrate scope of these methods is limited. Moreover, the direct sulfonylation of Pyrazolone by aryl sulfonyl chloride failed to give Pyrazolone sulfones. Thus, developing a more efficient method to synthesize Pyrazolone sulfones is very important. Materials and Method: Pyrazolone, aryl sulphonyl hydrazide, iodine, p-toluenesulphonic acid and water were mixed in a sealed tube, which was heated to 100°C for 12 hours. The mixture was cooled to 0°C and m-CPBA was added in batches. The mixture was allowed to stir for 30 min at room temperature. The crude product was purified by silica gel column chromatography to afford sulfuryl Pyrazolone. Results: In all cases, the sulfenylation products were formed smoothly under the optimized reaction conditions, and were then oxidized to the corresponding sulfones in good yields by 3-chloroperoxybenzoic acid (m-CPBA) in water. Single crystal X-ray analysis of Pyrazolone sulfone 4aa showed that the major tautomer of Pyrazolone sulfones was the amide form instead of the enol form observed for Pyrazolone thioethers. Moreover, the C=N double bond isomerized to form an α,β-unsaturated C=C double bond. Conclusion: An efficient method to synthesize Pyrazolone thioethers by iodine-catalyzed sulfenylation of Pyrazolones with aryl sulfonyl hydrazides in water was developed. Moreover, this method was employed to synthesize Pyrazolone sulfones in one-pot by subsequent sulfenylation and oxidation reactions.

  • p-Toluenesulfonic Acid-Promoted, I2-Catalyzed Sulfenylation of Pyrazolones with Aryl Sulfonyl Hydrazides.
    ChemInform, 2015
    Co-Authors: Xia Zhao, Lipeng Zhang, Guiyan Liu, Haomeng Wang
    Abstract:

    The I2-catalyzed cross-coupling of Pyrazolones with aryl sulfonyl hydrazides furnishes aryl Pyrazolone thioethers.

  • p toluenesulphonic acid promoted i2 catalysed sulphenylation of Pyrazolones with aryl sulphonyl hydrazides
    Chemical Communications, 2014
    Co-Authors: Xia Zhao, Lipeng Zhang, Guiyan Liu, Haomeng Wang
    Abstract:

    Aryl Pyrazolone thioethers were synthesized via the I2-catalysed cross-coupling of Pyrazolones with aryl sulphonyl hydrazides in the presence of p-toluenesulphonic acid, which has been proposed to promote the reaction by facilitating the decomposition of sulphonyl hydrazides.

Jianlin Han - One of the best experts on this subject based on the ideXlab platform.