Synthesis and Acaricidal Activity of Some New 1,2,4‐Triazine Derivatives

A new series of 1,2,4‐triazine derivatives were designed, synthesized, and identified on the basis of IR, ¹H‐NMR, ¹³C‐NMR, and EI‐MS spectral data. The potent acaricidal activity of 1,2,4‐triazine derivatives against eggs and adult female of Tetranychus urticae (Koch) was assessed compared with pyridaben under laboratory conditions. Structure acaricidal activity relationships of the promising 1,2,4‐triazine derivatives were analyzed for eggs and adult female; the nature and position of the substituents were important in demonstration of the activities.     

Chemoselective Synthesis of Enamino‐Coumarin Derivatives Identified as Potent Antitumor Agents

The reaction of 4‐aminocoumarin ( 2 ) with benzaldehyde gave the bisenamino derivatives 4 . Thus, transamination of 2 with o‐phenylenediamine furnished enamino skeleton 3 , which can be obtained from 1 . Reaction of 1 with 5‐aminoisoxazole afforded 5 . While reaction of 2 with benzalaniline, isatinanil and phenyl isothio cyanate afforded the corresponding 7 , 8 and 9 , respectively. Heterocyclic annulations of 2‐phenylthiazolidine‐4‐one 10 2‐phenylthiazolidin‐4‐one 10 and 2‐phenyl‐thiazinan‐4‐one 11 systems were achieved via reaction of 2 with benzaldehyde and rather either 2‐mercaptoacetic acid or 3‐mercaptopropanoic acid respectively. The behavior of 2 towards monochloro acetic acid and 4‐oxo‐4‐phenylbuatonic 4‐Oxo‐4‐phenylbutanoic acid was investigated. All of the newly synthesized compounds were evaluated as antitumor (cytotoxic) agents. Most of these compounds have shown significant antitumor activities.     

Effect of thermal treatment on the structure and texture of differently impregnated NiO/SiO2 catalysts

NiO/SiO₂ catalysts were prepared with Ni contents ranging from 2–15% using a microporous silica support at pH ~11.5. The role of the method of preparation on the resulting catalyst is also investigated. Structural and textural changes were followed using X-ray diffraction, TG and DTA techniques—the surface area measurements were carried out on the parent catalysts and those produced in the temperature range 250–1000°C.Impregnation of the silica gel in the nickel ammine complex solution (catalyst series 1N–4N) with subsequent drying at 80°C overnight produced crystalline catalysts with two distinct peaks at d-spacings of 2.035 and 2.349 Å resulting from a surface silicate. This is easily destroyed by thermal treatment at 250°C for Ni contents ? 10% but is stable to this temperature for the higher Ni content. Drying the catalyst at room temperature (3N_b) gives rise to an amorphous product. A non-crystalline catalyst is also obtained when concentrated ammonia solution is added to the adsorbed nickel salt (3N_c). At high Ni content, the hydroxo ligand becomes significant and results in a surface compound in which one silanol group is attacked. This gives rise to a crystalline product at 500°C with characteristic d-spacings at 2.201 and 2.049 Å which, subsequently, produces a poorly crystalline NiO product at 1000°C. The presence of this hydroxo ligand is manifested by a small endotherm at 260°C.At Ni contents below 15% but greater than 2% a small exotherm is observed at ~ 500°C resulting from a reduction process. Entrained SO₄^2? ions present as an impurity are evolved at temperatures & > 750°C and can be estimated by TG analysis.The specific surface area decreases with Ni contents ? 5% but increases for higher Ni contents. Catalyst samples containing 15% Ni possess the highest specific area at all temperatures.Pore structure analysis showed that microporosity increased with increase in Ni content for the catalyst series 1N–4N. Samples from preparations 3N_b and 3N_c showed more mesoporosity than that of 3N. Thermal treatment causes widening of the pores for catalysts 1N–3N becoming predominantly mesoporous, co-existing with some micropores. Catalyst samples with 15% Ni remained predominantly microporous-mesoporosity increasing only at 1000°C.     

Mathematical programming based heuristics for the 0–1 MIP: a survey

The 0–1 mixed integer programming problem is used for modeling many combinatorial problems, ranging from logical design to scheduling and routing as well as encompassing graph theory models for resource allocation and financial planning. This paper provides a survey of heuristics based on mathematical programming for solving 0–1 mixed integer programs (MIP). More precisely, we focus on the stand-alone heuristics for 0–1 MIP as well as those heuristics that use linear programming techniques or solve a series of linear programming models or reduced problems, deduced from the initial one, in order to produce a high quality solution of a considered problem. Our emphasis will be on how mathematical programming techniques can be used for approximate problem solving, rather than on comparing performances of heuristics.     

Vistas in the field of 1,3-oxathiolan-5-ones: Synthesis and chemical reactivity

This review covers many reports of the applications of multicomponent domino reactions (MDRs) in the synthesis of novel stereocontrolled mercapto-heterocycles from the 1972 up to the end of 2016. The reported approaches were employed for modifications of the oxathiolanone core for new construction of a mercapto-heterocycles scaffold from mercaptoacetyl transfer agent with various reagents.     

Advances in 4,6‐dimethyl-3-amino-3H-pyrazolo[3,4-b] pyridine-based and their annulated systems

Abstract

This review supply an inclusive survey of the recent progress in the chemistry of 4,6‐dimethyl-3-amino-3H-pyrazolo[3,4-b]pyridine concerning the synthesis and reactions and biological activity over the period from the year 1990 to the year 2020.     

Sustainable use of eggshell powder in the composite based on recycled polystyrene and virgin polystyrene mixture

One of the ideas to recycle plastic waste is to mix it with virgin plastic in order to produce sustainable material. In this study, recycled polystyrene (R-PS) is used as a mixing component with virgin polystyrene (PS). Besides, eggshell powder (ESP) was also incorporated to reduce the compounding cost of the composite. Effects of R-PS/PS weight percentage on properties of composites were studied. Increasing PS content has increased tensile properties and impact strength of composites. Results obtained from these properties are in good relation to SEM micrographs. More surprisingly, R-PS plays a crucial role in enhancing the thermal stability of composites. This is simply due to the impurities contained in R-PS.     

Synthesis and In Vitro Antitumor Activity of New Isoxazolo[5,4‐d]Pyrimidine Systems

The reaction of 5‐amino‐3‐methylisoxazole ( 1 ) with aldimines 2 , 3 , 4 , 5 , 6 , 7 gave basic side chain 5‐amino‐3‐methylisoxazole derivatives 8 , 9 , 10 , 11 , 12 , 13 . Annulations of derivatives 8 , 9 , 10 , 11 , 12 , 13 with anisaldehyde afforded the target isoxazolo[5,4‐d]pyrimidines 14 , 15 , 16 , 17 . Treatment of 1 with isatin ketimine anil 18 resulted in the formation of derivative 19 , which further cyclized with anisaldehyde afforded the spirotetracyclic system 20 . Mannich reaction of 1 with primary amine such as methylamine and benzylamine gave the corresponding isoxazolo[5,4‐d]pyrimidine derivatives 21 and 22 , respectively. The newly synthesized compounds were tested for their antitumor activity.     

Convenient synthesis,antimicrobial evaluation and molecular modeling of some novel quinoline derivatives

α, β-Unsaturated carbonyl compounds 2a, 2b, 3, and 4 were synthesized by the Knoevenagel condensation between 2-substituted quionoline-3-carboxaldehyde 1a and/or 1b with active methylene compounds. In addition, the synthesis of azlactone is achieved starting from 1a and N-acetylglycine. Synthesis of pyridine, pyrene, and pyrimidine derivatives 6–8 were accomplished via one-pot multicomponent reaction of 1b with acetyl acetone, malononitrile, and ammonium acetate; acetophenone, malononitrile, and NaOH; or acetyl acetone and urea in acidic medium. The new synthesized compounds showed good antimicrobial activities. The DFT calculations have been used to predict the electronic properties of the studied compounds.