alkali and alkaline earth metals hydrogen sulfate catalyzed the one-pot three component condensation reactions of aldehydes, 1,3-dicarbonyl compounds and urea or thiourea under solvent-free conditions leading to 3,4-dihydropyrimidin-2(1h)-ones in high yields at 80 °c. our results showed that biginelli reaction not only is ph dependent, but the cation of catalyst plays an important role.

oil exploration and production zones are very frequently contaminated with petroleum hydrocarbons or its derivatives. the most important exploration and production zones are located in south-west and south of the country, in iran. masjed soleiman city is located on an oil field. the soil of this region has been affected by the petroleum composition. mach petroleum seepages and springs (asphalt,...

the present research designed to evaluate the effects of foliar application of methyl jasmonate (meja), salicylic acid (sa) and potassium sulfate on improving fruit quality and photosynthesis system. ten treatments include: sa (0.3, 0.6 and 0.9 mm), meja (0.5, 1 and 2 mm), potassium sulfate (0.5, 1 and 1.5%) and distilled water (control) were sprayed on pomegranate trees 2 and 7 weeks after ful...

One-pot multicomponent condensation of β-naphthol, aromatic aldehydes, acetamide or urea in the presence of potassium hydrogen sulfate was carried out under solvent-free condition to afford amidoalkyl naphthols in 83%~96% yields.

abstract nitrogen is a key nutrient in plant growth and it is necessary for amino acid synthesis. sulfur has very important role in the biosynthesis of the alliums flavor and pungency precursors and potassium improve crop yield and quality. in order to study the effect of ammonium nitrate and potassium sulfate on concentration some of the mineral elements in onion (allium cepa l. azar shahr cv....

Alkali and alkaline earth metals hydrogen sulfate catalyzed the one-pot three component condensation reactions of aldehydes, 1,3-dicarbonyl compounds and urea or thiourea under solvent-free conditions leading to 3,4-dihydropyrimidin-2(1H)-ones in high yields at 80 °C. Our results showed that Biginelli reaction not only is pH dependent, but the cation of catalyst plays an importan...

A marked inhibition of the incorporation of S(35)-sulfate by normal calf costal cartilage was produced by potassium ascorbate in the presence of catalytic amounts of cupric ions. The effect of the various components of the ascorbic acid oxidizing system (potassium ascorbate, cupric ions, cuprous ions, hydrogen peroxide, dehydroascorbic acid) was investigated. The results of experiments in which...

Single crystals of KTb(C(2)O(4))(SO(4))(H(2)O), potassium aqua-terbium(III) oxalate sulfate, were obtained under hydro-thermal conditions. In the crystal structure, the Tb(III) atom is coordinated by four O atoms from two oxalate anions, three O atoms from three sulfate anions and one O atom from a water mol-ecule within a TbO(8) distorted square antiprismatic coordination. The potassium and te...

objective(s) the aims of present study were to elucidate the effect of nahs as a h2s donor on precontracted rat trachea smooth muscle, role of epithelium and nitric oxide in this action. materials and methods tracheal rings from male adult wistar rats were isolated and mounted in an organ bath containing krebs–henseleit solution under 1.5 g resting tension and contractions were recorded isometr...

The present research designed to evaluate the effects of foliar application of methyl jasmonate (MeJA), salicylic acid (SA) and potassium sulfate on improving fruit quality and photosynthesis system. Ten treatments include: SA (0.3, 0.6 and 0.9 mM), MeJA (0.5, 1 and 2 mM), potassium sulfate (0.5, 1 and 1.5%) and distilled water (control) were sprayed on pomegranate trees 2 and 7 weeks after ful...