A series of 3-(4-phenylisothiazol-5-yl)-2H-chromen-2-one (6a-l) derivatives has been efficiently synthesized by straightforward sequential reactions. Tandem Vilsmeier Hack reaction/cyclization/bromination/ Suzuki cross-coupling reactions were successfully applied to the preparation of title compounds in goodto-high yields. In the synthetic sequences, 3-chloro-3-(2-oxo-2H-chromen-3-yl)acrylaldehydes (2) were found to react with ammonium thiocyanate to yield the corresponding 3-(isothiazol-5-yl)-2H-chromen-2ones (3). These derivatives were brominated with N-bromo succinamide to yield the corresponding regioselective 3-(4-bromoisothiazol-5-yl)-2H-chromen-2-one (4). Finally, compound 4 was treated with various phenyl/pyrazole/7H-pyrrolo[2,3-d]pyrimidinyl boronic acids 5a-l in the presence of K 2 CO 3 and Pd catalyst in dimethylformamide to yield the corresponding title derivatives 6a-l. All the synthesized compounds were characterized by analytical and spectral studies. All the final compounds were screened against different cancer cell lines (A549, PC3, SKOV3, and B16F10), and among these compounds, 6b, 6g, 6h, and 6l displayed moderate cytotoxic activity against the tested cell lines. a IC 50 is defined as the concentration, which results in a 50% decrease in cell number as compared with that of the control cultures in the absence of an inhibitor, and was calculated using the respective regression analysis. The values represent the mean AE SE of three individual observations. Pale orange solid (338 mg), yield: 64%; mp: 289-291°C; IR (KBr) υ max (cm À1 );

A series of coumarin‐substituted 1,3‐thiazin‐2‐thione derivatives 4a–m were synthesized via the multicomponent reaction of 3‐chloro‐3‐(2‐oxo‐2H‐chromen‐3‐yl)acrylaldehyde (1) carbon disulfide (2), and various primary amines (3), in presence of triethylamine and acetonitrile under stirring with good yields. Compounds 4a, 4d, and 4m showed activity against A549, MDA‐MB‐231, MCF7, HeLa, and B16F10 cancer cell lines. In vitro anticancer result was supported by in silico docking and in silico ADME as well.

Metal/metal oxide‐decorated multiwalled carbon nanotubes (MWCNTs) have been found to be effective over various catalysts because of the synergistic, hybrid, physical, and chemical properties of such nanotubes. These properties make them highly active catalytic tools with excellent chemoselectivity, low catalyst loading, and high recyclability of the catalyst. Here, we discuss some recent findings related to the following topics: (1) synthesis of metal/metal oxide‐decorated MWCNTs, (2) characterization techniques of heterogeneous nanocomposites, and (3) application of these metal/metal oxide nanocomposites for the synthesis of heterocyclic compounds. This review emphasizes the main requirements for developing new nanocomposites for the synthesis of pharmaceutically important heterocycles.

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