Diaminoglyoxime as a versatile reagent in the synthesis of bis(1,2,4-oxadiazoles), 1,2,4-oxadiazolyl-quinazolines and 1,2,4-oxadiazolyl-benzothiazinones

Recent Advances in the Synthesis of Benzo[d]isothiazol-3(2H)-One and Benzo[e][1,3]Thiazin-4-One Derivatives

Benzo[d]isothiazol-3(2H)-one and benzo[e][1,3]thiazin-4-one derivatives, as significant sulfur- and nitrogen-containing heterocyclic compounds, are prevalent in natural products, pharmaceuticals, and food items. In recent years, a variety of innovative synthetic methodologies for these compounds have been developed. In this review, we will comprehensively introduce the major advances in the synthesis of benzo[d]isothiazol-3(2H)-one and benzo[e][1,3]thiazin-4-one derivatives via both intramolecular and intermolecular pathways from 2012 to the present.

Synthesis of 5-Trifluoromethyl-1,3-thiazin-4-one Compounds using Trifluoromethyl Acrylic Acid as a Synthon

A novel method has been developed for the synthesis of 1,3-thiazin-4-one compounds containing trifluoromethyl groups utilizing 2-trifluoromethyl acrylic acid and thioamides as key starting materials. This protocol is characterized by its simplicity, practicality, and tolerance toward various functional groups. Given the straightforward nature of the procedure, the ready availability of both starting materials, and the significance of drugs containing trifluoromethyl, it is anticipated that this reaction will have wide-ranging applications.

Nanocrystalline ZnO: A Competent and Reusable Catalyst for the Preparation of Pharmacology Relevant Heterocycles in the Aqueous Medium

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Nanoparticle catalyzed synthesis is a green and convenient method to achieve most of the chemical transformations in water or other green solvents. Nanoparticle ensures an easy isolation process of catalyst as well as products from the reaction mixture avoiding the hectic work up procedure. Zinc oxide is a biocompatible, environmentally benign and economically viable nanocatalyst with effectivity comparable to the other metal nanocatalyst employed in several reaction strategies. This review mainly focuses on the recent applications of zinc oxide in the synthesis of biologically important heterocyclic molecules under sustainable reaction conditions.

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Application of zinc oxide in organic synthesis: Considering the achievable advantages of this nanocatalyst, presently several research groups are paying attention in anchoring zincoxide or its modified structure in several types of organic conversions e.g. multicomponent reactions, ligand-free coupling reactions, cycloaddition reaction, etc. The advantages and limitations of this nanocatalyst are also demonstrated. The present study aims to highlight the recent multifaceted applications of ZnO towards the synthesis of diverse heterocyclic motifs. Being a promising biocompatible nanoparticle, this catalyst has an important contribution in the fields of synthetic chemistry and medicinal chemistry.

Double 1,4-addition of (thio)salicylamides/thiosalicylic acids with propiolate derivatives: a direct, general synthesis of diverse heterocyclic scaffolds

A simple and practical ring-closure procedure to prepare a range of diverse heterocycles has been developed.

Synthesis of 2-(1,2,4-oxadiazol-3-yl)quinazolin-4(3H)-ones from diaminoglyoxime-based nitrones

Various 2-[5-(aryl)-1,2,4-oxadiazol-3-yl]quinazolin-4(3H)-ones have been synthesized from the reaction of diaminoglyoxime-based nitrones with methyl 2-aminobenzoate or 2-aminobenzamide in the presence of acetic acid at 100 °C. The reaction was extended as a one-pot three-component approach starting from diaminoglyoxime, aldehyde and methyl 2-aminobenzoate.