A sequential process strategy was introduced for the synthesis of 2,3,4,5-tetrasubstituted pyrroles by the formation of benzoin from the corresponding aromatic aldehyde and followed by condensation reaction with 1,3-dicarbonyl compounds and ammonium acetate in the presence of diethylene glycol-bis(3-methylimidazolium) dihydroxide as catalyst in refluxing ethanol. The recycled catalyst could be ...

A series of 2-amino pyridine-3-carbinitrile derivatives incorporated coumarin moiety has developed via multicomponent condensation of 3-acetyl-2H-chromen-2-one, arylaldehydes, malononitrile and ammonium acetate utilizing Brønsted acidic ionic liquid, (4-sulfobutyl)tris(4-sulfophenyl)phosphonium hydrogen sulfate as catalyst under solvent-free conditions. Good yields, short reaction times, straig...

The methods commonly used for precipitating aluminum by 8-hydroxyquinoline from an acetic-acid solution, buffered with ammonium acetate, do not sufficiently define the conditions requisite for complete precipitation. The present article describes a method in which aluminum is precipitated as the oxyquinolate from a solution which has been partially neutralized with ammonium hydroxide, using bro...

Denitrification and dissimilatory reduction to ammonium (DNRA) are competing nitrate-reduction processes that entail important biogeochemical consequences for nitrogen retention/removal in natural and man-made ecosystems. The nature of the available carbon source and electron donor have been suggested to play an important role on the outcome of this microbial competition. In this study, the inf...

Heat, acid, base, UV radiation and oxidation stress methods were applied to study the stability of cough-cold products containing acetaminophen, phenylephrine or phenylpropanolamine hydrochloride and chlorpheniramine maleate. Liquid chromatography coupled with mass spectrometry was used to analyze the degraded samples and obtain molecular weights information. Different volatile buffers (ammoniu...

An extracellular protease of Staphylococcus aureus, strain V8, previously shown to cleave specifically the peptide bonds on the carboxyl-terminal side of either aspartate or glutamate residues in phosphate buffer (pH 7.8) hydrolyzes only glutamoyl bonds in either ammonium bicarbonate (pH 7.8) or ammonium acetate (pH 4.0). Of all aspartoyl bonds tested, only the Asp-Gly linkage is cleaved at a d...

Analytical isotachophoresis has proved to be an excellent method for separation and quantitative measurement of ionic species in biologic fluids. Isotachophoretic separation of cations in presence of a complex-forming nonionic detergent (e.g. Triton X-100) in 98% methanol enables simultaneous quantitative determination of ammonium, sodium, potassium, magnesium, and protonated creatinine in urin...

An efficient synthesis of polyhydroquinoline derivatives was reported via four-component coupling reactions of aldehydes, 1,3-dicarbonyl ketones (dimedone or 1,3-cyclohexanedione), ethyl acetoacetate or methyl acetoacetate and ammonium acetate in the presence of a catalytic amount of nanocrystalline TiO2 under solvent free conditions. The reported method is mild, rapid and has the advantages su...

An efficient synthesis of polyhydroquinoline derivatives is achieved via Hantzsch condensation reaction between aldehydes, dimedone, ethyl acetoacetate and ammonium acetate in the presence of catalytic amount of SFHS in ethanol. This method gives remarkable advantages such as shorter reaction time, simple workup procedure and good to excellent yields. Furthermore the catalyst can be recovered c...