Synthesis and characterization of sulfide, sulfoxide and sulfone derivatives of thiopyran: antimicrobial evaluation

Facile one-pot, multi-component reaction to synthesize spirooxindole-annulated thiopyran derivatives under environmentally benevolent conditions

An efficient and facile one-pot, five-component reaction for the synthesis of 2,6-diamino-1-alkyl-2-oxospiro[indoline-3,4′-thiopyran]-3,5-dicarbonitrile derivatives has been reported by a reaction between primary amines, carbon disulfide, malononitrile, and isatin derivatives. The major advantages of this procedure are high yields of products in relatively short reaction time, scalability, mild conditions, multi-component synthetic procedure, low catalyst loading, no column separation and simple reaction work-up. As a consequence, this synthetic procedure provided an efficient access to spirooxindole-annulated thiopyran derivatives.

Role of sulphur-heterocycles in medicinal chemistry: An update

From many decades, S-heterocycles have maintained their status as an important part and core of FDA approved drugs and medicinally active compounds. With exhaustive exploration of nitrogen heterocycles in medicinal chemistry, researchers have shifted their interest towards other heterocycles, especially, S-heterocycles. Thus several attempts have been made to synthesize a variety of new sulphur containing compounds with high medicinal value and low toxicity profile, in comparison to previous N-heterocycles. Till today, S-heterocycle containing compounds have been largely reported as anticancer, antidiabetic, antimicrobial, antihypertension, antivral, antinflammatory etc. In this review, the authors have tried to provide a critical analysis of synthesis and medicinal attributes of sulphur containing heterocycles such as thiirane, thiophene, thiazole, thiopyran, thiazolidine etc reported within last five years to emphasize the significance and usefulness of these S-heterocycles in the drug discovery process.

Synthesis and Characterization of Novel Thiazolo[3,2-a]pyrimidine Derivatives and Evaluation of Antioxidant and Cytotoxic Activities

A series of novel thiazolo[3,2-a]pyrimidines were synthesized and characterized by FT-IR, ¹ H, ¹³ C-NMR and mass techniques. Their antioxidant activities were investigated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and the results showed that all the synthesized compounds exhibit good antioxidant activity. In addition, it was found that any substituent on the aromatic ring of the products plays an important role in their antioxidant activity. In vitro cytotoxicity of compounds 4a-4j was investigated using MTT cell viability assay. Among these compounds, 6-ethyl 2,3-dimethyl 5-(4-chlorophenyl)-7-methyl-2,3-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidine-2,3,6-tricarboxylate (4e) bearing a chlorine substituent displayed the highest cytotoxic effect (IC₅₀ =6.26±0.6 μm) in comparison with doxorubicin (IC₅₀ =0.68±0.1 μm) as a standard after 72 h. Therefore, it is assumed that these compounds could be used as effective antioxidant and cytotoxic agents.