A highly efficient substitution of the vinyl fluoride of perfluoroketene dithioacetals was achieved using trimethylsilylacetate to give 2-perfluoroalkyl succinic acid derivatives and 2-trifluoromethyl succinimides. This chain process was initiated by a catalytic amount of fluoride salt, whereas ...

Heterogeneous azeotropic distillation is a widely used process in the chemical process industries for the separation of binary azeotropic mixtures into their constituent pure components. It involves the addition of an entrainer which is partially miscible and forms a heterogeneous azeotrope pref...

Thermal decomposition of n-propyl (C3H7ONO2, PPN) and n-butyl (C4H9ONO2, BTN) nitrates has been studied in a low pressure flow reactor combined with a quadrupole mass spectrometer. The rate constants of the nitrates decomposition were measured as a function of pressure (0.95–12.8 Torr of helium...

In this paper, the electrochemiluminescence (ECL) behavior of a hole-transport polymer, poly [9,9-bis(3'-(N,N-dimethylamino) propyl)-2,7-fluorene]-alt-2,7-(9,9-dio ctylfluorene)] (PFN) was examined with the purpose of finding a novel organic ECL emitter. It was found that the PFN exhibits s...

Liquid-liquid equilibrium (LLE) for the quaternary system propionic acid + n-propanol + n-propyl propionate + water and for the ternary sub-systems propionic acid + n-propyl propionate + water and n-propanol + n-propyl propionate + water were studied at 293.15, 313.15 and 333.15 K and atmospheri...

An extracellular lipase partially purified from Bacillus thermoamylovorans BHK67 was effectively immobilized onto modified magnetic MgFe2O4 nanoparticles (NPs). NPs were prepared by the sol-gel auto-combustion method and characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diff...

The characteristics of N-propyl-N′-ethoxycarbonyl thiourea (PECTU) were studied in the flotation experiments of chalcopyrite and pyrite compared with butyl xanthate (BX). The interaction mechanism between mineral and PECTU was investigated according to zeta potential and electrochemistry measur...

The production of n-propyl acetate by transesterification is an environmentally and economically beneficial option for handling a huge amount of methyl acetate from the polyvinyl alcohol industry. This article proposes several energy-saving transesterification processes by combining pressure-swi...

17(20)-dehydro-23,24-dinorcholan-22-oic acids, derived from natural sterols are converted with H2O2 in the presence of molybdate or tungstate ions into 16-unsaturated 20-oxo-pregnanes, which are useful intermediates of corticosteroid hormones and drugs.

The aim of this study was to synthesize different ester derivatives of dehydroepiandrosterone with therapeutic potential as antiandrogens.The biological effect of these steroids was demonstrated in in vivo as well as in vitro experiments. In the in vivo experiments, we measured the activity of s...

Steroidal epoxy and/or N-oxy 17-picolyl and 17-picolinylidene-androst-5-ene derivatives have been prepared using 3β,17β-dihydroxy-17α-picolyl-androst-5-ene (1), 3β-acetoxy-17-picolinylidene-androst-5-ene (2), and 3β-hydroxy-17-picolinylidene-androst-5-ene (3) as synthetic precursors. The co...

A large number of α-naphthyl selenium and tellurium compounds (1–14) have been prepared through two different methods. The first method involves the alkylation of sodium 1-naphthylselenolate/tellurolate, generated in situ using hydrazine hydrate as reducing agent while the second method involv...

1,4-Bis(diphenylphosphino)butane and 1,5-bis(diphenylphosphino)pentane add two molecules of 6-bromo-1,2-naphthoquinone to afford bis-ylides which on treatment with protic acids are converted into the corresponding P,P’-bis(7-bromo-3,4-dihydroxy-1-naphthyl)-substituted bis-phosphonium salts.

α,ω-Bis(naphthylseleno)alkanes [C10H7Se(CH2)nSeC10H7] (1a–c), where n = 1–3, have been prepared through two different methods. One of the two methods involves the alkylation of sodium 1-naphthylselenolate, generated by the Se–Se bond reduction of dinaphthyl diselenide using hydrazine hydrat...

The electrochemical reduction of a mono-chelate palladium dichloride complex with 1,2-bis(diphenylphosphino)ethane (dppe) in DMF results in formation of highly reactive mono-chelate palladium(0) complex, which reacts with initial complex by reaction of the ligand abstraction forming stable bisch...

The paper presents a rapid method for the determination of dioxopromethazine hydrochloride (DPZ), an antihistamine drug, by the capillary electrophoresis with electrochemiluminescene detection (CE–ECL) using tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)32+) reagent. This CE–ECL detection method ...

Synthetic procedures are described that allow access to new copper(II) complexes with dipeptides containing the α-aminoisobutyric residue (Aib) as ligands. The solid complexes [Cu(H−1LA)]n·nH2O (1) (LAH=H-Aib-Gly-OH), [Cu(H−1LB)(MeOH)]n·nMeOH (2) (LBH=H-Aib-l-Leu-OH) and [Cu(H-1LC)]n (3) (LCH...

A series of 10 N(9)- and N(9)-acyclonucleosides of guanine and 8-substituted guanines (8-Br, 8 8-SH, and 8-NH2), and two N(7)-acyclonucleosides of hypoxanthine, were tested for their ability to inhibit purine nucleoside phosphorylase (PNP) (E.C. 2.4.2.1) from human erythrocytes and rabbit kidney...

Hibiscus sabdariffa (Malvaceae) is a plant that is widely recognised for its antihypertensive properties; however the constituent(s) responsible for this biological activity are presently unknown. The aim of this study was to identify the potential compounds that are responsible for the vasorela...

Reactions of 1,3-disubstituted 5-aminopyrazole-4-carbonitrile derivatives (3a-o) with dimethyl acetylenedicarboxylate in the presence of potassium carbonate in dimethyl sulfoxide gave the corresponding dimethyl 1,3-disubstituted pyrazolo[3,4-b]pyridine-5,6-dicarboxylates (4a-o) which were allowe...