In this work, a variety of highly substituted quinolines were readily synthesized via Friedlander annulation using Br?nsted acid silica-based sulfonic acid as a modified catalyst under solvent-free conditions at room temperature. This efficient procedure has the advantages of giving the target compounds in high yields, short reaction times, simple workup procedure, reusability of the catalyst, and environmentally benign conditions.

The title compound 3-amino-5-(4-chlorophenyl)pyridazine-4-carbonitrile was prepared by a one-pot three-component reaction of malononitrile with corresponding arylglyoxal in the presence of hydrazine hydrate at room temperature in water and ethanol. Its structure was also con?rmed by its IR, 1H, 13C-NMR, Mass spectral data and elemental analysis. The compound was crystallized in the monoclinic system, space group P21/c, a = 3.817(3) ?, b = 13.533(10) ?, c = 19.607(15) ?, B = 93.401(10)°, Z=4, R1 = 0.0906 and wR2 = 0.1422. The crystal structure of the compound also shows a weak intermolecular interaction between N1 atom of one molecule and N3 atom of the other molecule.

Glacial acetic acid as a protic acid was employed as a catalyst in a solvent free condition for facile preparation of di(indolyl)methanes (DIMs) via one-pot condensation of indole with aryl or heteroaryl aldehydes. Various aryl and heteroaryl aldehydes were efficiently converted to the corresponding di(indolyl)methanes (1a-p) in high yields. The described novel synthetic method proposes several advantages of safety, mild condition, short reaction times, high yields, simplicity and the inexpensively glacial acetic acid compared to other catalysts.

A highly sensitive, accurate and simple spectrophotometric method was established for determination of naproxen (NAP). The method involved ion-pair complex formation between naproxen and bromophenol blue (BPB). The colored product was measured at 432 nm. The reaction conditions were optimized. The absorbance was found to increase linearly with increase in concentration of NAP which was corroborated by correlation coefficient value. Beer’s law was obeyed in the concentration range of 1-110 µg mL-1 with molar absorptivity of 9.756×103 L mol-1 cm-1. The limits of detection (LOD) and quantitation (LOQ) for the proposed method are 0.292 and 0.973 µg mL-1, respectively. Recovery of the method was carried out by standard addition method. Recovery studies and statistical data proved the accuracy, reproducibility and the precision of the proposed method. The common excipients did not interfere in this analysis. Hence the method is useful for routine estimation of naproxen in pharmaceutical formulation and human serum samples.

An inexpensive straightforward approach to direct oxidative twofold C-H arylation of 1,4-naphthoquinone catalyzed by readily available Br?nsted acids was developed. Under the simple and easily achievable reaction conditions, electron-rich aromatics undergo Friedel-Crafts type functionalization to furnish 2-arylonaphthoquinones in good yields. The attempt to rationalize the scope and limitation of the approach based on desktop PC DFT calculation and reactivity indexes theory was taken up.

Ferrocene and their derivatives are well-known redox active materials and were extensively used by construction of modified electrodes for the design of electrochemical sensors and biosensors. Substituent derivatization of ferrocene offers the prospect of controlling ferrocene moiety properties such as solubility, stability, reversibility of oxidation wave (important for their role as an electron transfer mediator) and oxidation potential, which is critical in the electrochemical determination of biological compounds. A new series of rigid alkynylferrocene including of 2-ferrocenylethynyl fluoren (3a), 2-ferrocenylethynyl fluoren-9-one (3b), 4-ferrocenylethynyl aniline (3c) and 3-ferrocenylethynyl-1-trifluoromethyl benzene (3d) have been prepared in good yields by Sonogashira coupling reaction. All products were characterized by 1H and 13C NMR, FT-IR, and elemental analysis. The redox chemistry of these compounds has been investigated by cyclic voltammetry. The half-wave potential of the terminal ferrocenyl moieties increases progressively in the order of 3c & LT; 3a & LT; 3b & LT; 3d, which is consistent with the electron density on the ferrocenyl unit.

A mild and efficient procedure has been proposed for oxidation of benzylic alcohols to the corresponding carbonyl compounds using polymer-supported dichloroiodate (PSDI). The oxidations were carried out in acetonitrile solution, affording the corresponding aldehydes or ketones in high substrate conversion and short reaction time under mild aprotic conditions. Excellent selectivity was observed between primary benzyl alcohols and secondary ones as well as non-benzylic alcohols in the oxidation reactions. The catalyst can be easily prepared and regenerated.

A green and efficient method for the synthesis of (4 or 5)-aryl-2-aryloyl-(1H)-imidazoles via self-condensation reaction of arylglyoxal hydrates in the presence of ammonium acetate using water as solvent under ultrasonic irradiation was reported. The reactions proceeded in high yields and very short reaction time. Introduced procedure is completely ecofriendly and don’t need any toxic organic solvent in all performing steps. In addition, we use computational chemistry for acquiring some information about the thermochemistry and geometrical structure of these imidazole derivatives.

In these studies, we had observed polyaniline (PANI) supported p-toluene sulfonic acid (TsOH) and FeCl3 (PANI- TsOH, PANI-FeCl3) as excellent reusable solid acid catalysts for the synthesis of 1, 8-dioxo-octahydroxanthene derivatives 4(a-g) under solvent-free grinding method at mild conditions. Additionally, in the same optimized condition ferric nitrate nonahydrate also acted as (non-reusable) very reactive inexpensive Lewis acid catalyst. The ferric nitrate nonahydrate lost its activity in the form of Clayfen (Clay-supported ferric nitrate) catalyst.

A series of some new (E)-2-(arylbenzylidene)-2-((4-methoxyphenyl)amino)acetohydrazides 4(a-j) have been conveniently synthesized by intermolecular oxidative cyclization of (E)-2-(arylbenzylidene)-2-[(4-methoxyphenyl)amino]acetohydrazides promoted by iodobenzene diacetate as an oxidant. The structures of the synthesized compounds have been confirmed by 1H NMR, IR, MS and elemental analysis. All the synthesized compounds were tested for their inhibitory action against clinically isolated strains i.e., Bacillus subtilis, Staphylococcus aureus, Xanthomonas campestris, Escherichia coli and Fusarium oxysporum. Compounds 4f (21-28 mm, 73.8 %), 4i (20-24 mm, 72.4 %) and 4j (21-27 mm, 71.6 %) demonstrated good antimicrobial activity against all the tested bacterial and fungal strains.