1-(2,5-Dichlorophenyl)hydrazine was converted via Fischer synthesis with isopropylmethylketone into 4,7-dichloro-2,3,3-trimethyl-3H-indole. Exposure of the indolenine to the vilsmeier reagent produced amino methylene malondialdehyde which reacted with hydrazine, arylhydrazine, urea, cyanoacetamide and thiourea to give pyrazols, pyrimidones and thiopyrimidone, respectively.

A series of pyrido[2,3-b]pyrazine derivatives were synthesized in good to excellent yields by condensation reactions of arylglyoxals with 2,3-diaminopyridine in dimethylformamide and ethanol at 90 oC.

Nano silica phosphoric acid (nano SPA) was applied as a catalyst for synthesis of 14-aryl/alkyl-14H-dibenzo[a,j]xanthenes and tetrahydrobenzo[a]xanthen-11-ones in microwave oven under solvent free conditions. High efficiency, easy availability and reusability are some advantages of this catalyst.

2,4,5-Trisubstituted imidazoles have many pharmaceutical properties and can be prepared via reaction of 1, 2-diketones with aldehydes in the presence of an acidic catalyst. In this work, we have prepared 2,4,5-trisubstituted imidazoles in the presence of trichloromelamine as a source of positive chlorine. Short reaction times, high yield, simplicity of operation and easy work-up are some advantages of this method.

The title compound 3-(4-hydroxy-3-methoxyphenyl)-7,7-dimethyl-7,8-dihydrocinnolin-5(6H)-one (3) was prepared via one-pot three component reaction of 2-(4-hydroxy-3-methoxyphenyl)-2-oxoacetaldehyde with dimedone in the presence of hydrazine hydrate and studied by the single crystal X-ray diffraction method. Its structure was also con?rmed by IR, 1H and 13C NMR spectroscopy. Compound 3 was crystallized in the monoclinic system, space group P21/c, a = 7.921(2) ?, b = 11.566(4) ?, c = 16.986(6) ?, B = 107.338(5)°, V = 1485.5(8) ?3, Z = 4, R1 = 0.0559 and wR2 = 0.1253. The crystal structure of 3 also shows a weak interaction between O3 and N2 atoms.

A new and simple method for the preconcentration and spectrophotometric determination of trace amounts of nickel was developed by cloud point extraction (CPE). In the proposed work, dimethylglyoxime (DMG) was used as the chelating agent and Triton X-114 was selected as a non-ionic surfactant for CPE. The parameters affecting the cloud point extraction including the pH of sample solution, concentration of the chelating agent and surfactant, equilibration temperature and time were optimized. Under the optimum conditions, the calibration graph was linear in the range of 10-150 ng mL-1 with a detection limit of 4 ng mL-1. The relative standard deviation for 9 replicates of 100 ng mL-1 Ni(II) was 1.04%. The interference effect of some anions and cations was studied. The method was applied to the determination of Ni(II) in water samples with satisfactory results.