a simple and efficient method for synthesis of tetrahydropyrimido[4,5-b]quinoline derivatives via three component reaction of aromatic aldehydes, dimedone and 6-amino uracil derivatives using a catalytic amount of sulfonic acid functionalized nanoporous silica (sba-15-pr-so3h) is described. the advantages of this method are easy and clean work-up, high yield, mild reaction condition, reusable c...

in this study, precipitated calcium carbonate (pcc) was modified using cationic starch, and its effect on optical and physical properties of paper was examined in comparison with unmodified filler afterwards. to determine the filler retention in paper, both modified and unmodified fillers were added to pulp suspensions by 20, 30, and 40 percentages. for comparing the utilization effect of modif...

efficient and one-pot synthesis of 1,8-dioxo-octahydroxanthenes was described by knoevenagel condensation, michael addition and cyclodehydration of dimedone. this reaction was carried out through condensation of dimedone and various aromatic aldehydes in the presence of task-specific brønsted acidic ionic liquid under solvent free conditions. the catalyst could be recycled five times without si...

introduction: this report describes the synthesis of 2-amino-2-deoxy(s-benzoylthioacetyl)-d-glucose (s-bz-ta-dg), radiolabeled with [99mtc(co)3(oh2)3]+ complex with a procedure including deprotection of the benzoyl group, characterization by hplc using a c18 reverse phase column and preliminary biodistribution study in normal mice. methods: [99mtc(co)3(h2o)3]+ complex was used to label ta-dg w...

a convenient synthesis of different types of polyfunctional dihydropyrrol-2-ones via one-pot four component reactions of formaldehyde, dialkyl acetylenedicarboxylates and amines, catalyzed by trichloroacetic acid (cl3cco2h) at room temperature has been investigated. the significant advantages of this synthetic method are mild reaction conditions, available and inexpensive material, short reacti...

in order to investigated the effect of flooding, different nutrition levels an anti-oxidant characteristics, chlorophyll fluorescence, amount of chlorophyll (a, b) and carotenoids leaves soybean (glycine max (l.) merr), cultivar dpx research at the university of agricultural sciences and natural resources, gorgan, in a completely randomized design to factorial arrangement with three replication...

the aim of this study was to investigate the effect of different concentration of royal jelly’s fatty acids (0.0, 125, 250, 500, 1000 µg/ml and 50 µl dmso) on in vitro maturation of goat oocyte. goat ovaries were collected from local slaughterhouse and transported to the laboratory and cocs were cultured into the maturation media supplemented with different concentration of royal jelly’s fatty ...

sulfonic acid functionalized sba-15 (sba-pr-so3h) as a new nanoporous acid catalyst was used in the one-pot synthesis of polyhydroquinolines derivatives via the hantzsch four component condensation reaction of aldehydes, b-ketoesters, dimedone and ammonium acetate under solvent free conditions with short reaction time in excellent yields. sba-pr-so3h was proved to be an efficient heterogeneous ...

lunar and mars landing is a crucial part of any exploration mission. its importance is manifested by the considerable interest in the past couple of decades. solution of lunar descent can be either numerical or analytical. numerical solutions are iterative and computationally demanding and some of them might not be suitable for on-board implementation. on the other hand, analytical solutions ar...

a simple, clean, and environmentally benign three-component process for the synthesis of 2-amino-4hchromenes using [mim]cl, as an efficient catalyst under solvent-free conditions are described. a wide range of aromatic aldehydes easily undergoes condensations with 1-naphthol and malononitrile under solvent-free conditions to afford the desired products of good purity in excellent yields. taking...