An efficient and green approach for the preparation of novel isatin-based conjugates with 2-amino thiazol-4-ones is described by the one-pot reaction of isatin derivatives, rhodanine, and secondary amines in the presence of magnesium oxide nanoparticles as a heterogeneous catalyst in water as a green solvent at room temperature. This new protocol provides products in good yields and short reaction times using a simple work-up procedure. The structure of one representative compound has been confirmed by X-ray single-crystal analysis.

A series of novel benzothiazole-substituted 4-thiazolidinones were synthesised by the one-pot reaction of rhodanine-3-acetic acid derivatives, 2-aminothiophenol, and triphenyl phosphite in the presence of nano silica-bonded 5-n-propyl-octahydro-pyrimido[1,2-a]azepinium chloride (NSB-DBU) as heterogeneous reusable nanocatalyst under solvent-free conditions in high yields.

A facile one-pot synthesis of novel oxindole derivatives bearing benzothiazolylmethyl-2-thioxothiazolidin-4one was accomplished via one-pot reaction of 5-oxoindolinylidene rhodanine-3-acetic acid derivatives, 2-aminothiophenol, and triphenyl phosphite in the presence of tetrabutylammonium bromide (TBAB) and nano silica-bonded 5-n-propyloctahydro-pyrimido[1,2-a]azepinium chloride (NSB-DBU) as heterogeneous reusable nanocatalyst. The target compounds were obtained in excellent yields (85%-92%) and short reaction times under fairly mild reaction conditions.

A simple and efficient synthesis of novel spirooxindoleefuran derivatives has been investigated by a modified version of the"interrupted" FeisteB enary (IFB) reaction of isatin derivatives, 1,3-dicarbonyl compounds and N-phenacyl pyridinium salts in the presence of triethylamine. The reaction has been carried out under mild conditions in ethanol, and the products were obtained in good to moderate yields with a simple work-up procedure.

A mild and efficient protocol for the synthesis of 2-amino-5-arylidene-1,3-thiazol-4(5H)-ones is reported by three component reaction of aldehydes, rhodanine and secondary amines in the presence of magnesium oxide nanoparticles as heterogeneous nanocatalyst in good yields and short reaction times.