Reaction of methyl 2-aryl-5-(chlorosulfonyl)-1,3-oxazole-4-carboxylates with 1H-pyrazol-5-amines and 1H-1,2,4-triazol-5-amines proceeds with the participation of endocyclic aminoazole nitrogen atoms to yield products containing a primary amino group. Being treated by sodium hydride these products undergo a further transformation into the tricyclic compounds. It has been shown that the cyclocondensation pathway includes the Smiles rearrangement with extrusion of SO2 followed by the elimination of MeOH. This reaction sequence is a convenient approach to the synthesis of new annulated [1,3]oxazolo[5,4-d]pyrimidine derivatives.

An efficient, three-component, catalyst free synthesis of dipyrazolo[1,5-a:3',4'-d]pyramid scaffolds has been carried out using 3-methyl-1H-pyrazol-5(4H)-one (1), 5-amino pyarazole (2a-b) and substituted aromatic aldehydes. The reaction underwent cyclocondensation reaction in reflux condition with moderate to good (62%–90 %) yields. The twenty newly prepared molecules were analyzed by means of 1H & 13C NMR, Mass, and IR spectroscopies and their activities against the bacterial and fungal strains were screened. Some of tested compounds have shown excellent antibacterial activities while another four were found to have good antifungal activity.

In this article, magnetically nanoparticles (MNPs) of CuFe2O4 were prepared and characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction and transmission electron microscopy techniques. Super paramagnetic CuFe2O4 was used as an efficient catalyst for green formylation of structurally diverse alcohols to the corresponding formyl esters using formic acid as a solvent (60-70 °C). All reactions were carried out successfully within 1-120 min to afford the products in 76-96 % yields. Reusibility of CuFe2O4 MNPs was examined 5 times without significant loss of its catalytic activity.