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.

The current study presents the synthesis of thiophene-appended pyrazoles through 3+2 annulations of chalcones 3(a-g)with aryl hydrazine hydrochlorides 4(a-d) in acetic acid (30%) under reflux conditions produced the thiophene-pyrazole hybrids 5(a-g) in good yields. Structures of synthesized new pyrazoles were confirmed by spectral studies, and elemental analysis. Further, preliminary biological evaluation studies show that compounds 5b and 5f having chloro substitution only in the thiophene ring exhibited excellent inhibition (12.5-25.0 µg/mL) against all the tested organisms in comparison with that of the standard. Compounds, 5a, 5c and 5g having electronegative chloro substitutions each in the aromatic and thiophene rings showed excellent (12.423-31.213 µg mL^-1) DPPH radical scavenging potencies. The synthesis of pyrazoline derivatives and the efficacy of some of the synthesized molecules as antimicrobial and antioxidant agents validate the significance of this study.

Aripiprazole is a widely used antipsychotic approved by the FDA (Food and Drug Administration) in 2002. Methods for preparation of aripiprazole mainly involve the use of expensive and toxic solvents, and the reaction time can be even several hours long. Our method allows to obtain aripiprazole with a yield of approximately 70–80% over just a few minutes using solvent-free conditions in the presence of PTC (Phase Transfer Catalysts) and microwave radiation.

In this paper, the synthesis of arylidene heterobicyclicpyrimidinones and thiones is reported by condensation of aromatic aldehydes, cyclopentanone, and urea or thiourea in the present of FePO4 as the green and recyclable catalyst. Using solvent-free conditions, non-toxic and inexpensive materials, simple and clean work-up, relatively short reaction times, and high yields of the products are the advantages of this method. Also, some new derivatives of arylidene dihydropyrimidinones and thiones were prepared by this green method.

Kinetic study of oxidation of toluidine blue (TB+) by periodate was carried out in aqueous medium and also in the cetyl trimethyl ammonium bromide (CTAB) reverse micellar medium. In both the media reaction obeys first order kinetics with respect to each of the reactants. In the reverse micellar medium, the reaction is forty times faster compared to aqueous medium under identical experimental conditions. The pronounced acceleration is accounted for by the lower micro polarity and the concentration effect present in the bound water of reverse micelles. In CTAB reverse micellar medium, the pseudo first order rate constant (k’) of the reaction is almost constant at all values of W, {W=[H2O]/[CTAB]} indicating that the reaction takes place on the micellar surface and results were explained by modified Berezin pseudo phase model..

A clean and efficient, mediated in water and assisted by ultrasound method for the synthesis of a series of N-substituted 1-amino-3-ferrocenyl-3-oxoprop-1-enes starting from acetyl ferrocene was developed. Our approach offers shortening of the reaction time under the mild reaction conditions and easy work up procedure.

Pioglitazone hydrochloride (PGH) is an oral anti-hyperglycemic agent used in the treatment of type-2 diabetes mellitus. Potassium permanganate was found to oxidize PGH both in acidic and basic conditions, based on which two simple and sensitive methods were developed for its determination in bulk sample and tablets, and validated. In the first method (indirect method), PGH was reacted with a measured excess of standard permanganate in H₂SO₄ medium, and the residual oxidant was determined by measuring its absorbance at 550 nm. The second method (Direct method) entails treating PGH with permanganate in NaOH medium, followed by the measurement of the resulting bluish-green manganite at 610 nm. Experimental variables affecting the reactions were studied and optimized. Under optimum conditions, linear relationships with good correlation coefficients were found between absorbance and concentration in the ranges, 1.25 – 25 µg mL^-1 (Indirect method) and 1-12 µg mL^-1 (Direct method) with respective molar absorptivity values of 1.10 × 10⁴ and 2.77 × 10⁴ l mol^-1 cm^-1. The limits of detection (LOD) and quantification (LOQ) were 0.36 and 1.08 (Indirect method) and 0.23 and 0.69 µg mL^-1 (Direct method). Intra-day and inter-day precisions were satisfactory, with %RSD values of ≤2.11, and the respective accuracies were excellent with %RE values of ≤2. The methods were also validated for robustness, ruggedness and selectivity. The methods were applied to the determination of PGH in its tablets with good accuracy and precision, and no interference from the tablet additives was encountered. The results were also compared with those obtained by a reference method.

An ecofriendly methods for the synthesis of medicinally important class of heterocyclic scaffold, pyrazole 4-carbonitrile derivatives by one pot three component reaction of malononitrile, phenyl hydrazine and aromatic aldehyde has been achieved at room temperature. Greener protocols of reaction are followed by using sodium chloride to accelerate the reaction in aqueous media. Present methodology is a condition based divergence on synthesis of pyrazole by using simple salts, which offers several advantages like use of aqueous media and high yield of product along with short reaction time, simple work up procedure, no waste or by products, avoid the use of heavy metals or nanoparticles are the fascinating characteristics of reaction.