objective: the aim of this study is to measure the effect of different condensation pressure on the microleakage of mineral trioxide aggregate (mta).  methods: this study was an invitro study. a total of 55 single rooted straight-canal human extracted sound teeth free of cracks or calcification were selected. teeth were sectioned from cej region at 3 mm above the root apex. remaining specimens ...

A protocol for the isothiourea-catalysed transfer hydrogenation of ?,?-unsaturated para-nitrophenyl esters using Hantzsch ester has been developed. Good to excellent yields are observed aryl bearing electron-withdrawing ?-substituents. The products can either be isolated directly in moderate (7 examples, 16–98%) or converted corresponding methyl (2 68–70% yield) benzyl amides 44–88% after situ ...

Two new ligand systems related to the previously described DOTTADs have been generated in a simple one step reaction. The first, trans-DOTTADs, were formed by Vilsmeier formylation (followed by cyclisation and N-demethylation) of 2,6-dimethyl-3,5-pyrazine-dicarboxylic acid, to give the novel bis-pyridinopyrazine dialdehyde ligands. The corresponding pyrazine diester, reacted similarly to an int...

A series of 3,5-(substituted)oxycarbonyl-1,4-dihydro-2,6-dimethyl-4-(substituted)pyridines (1a-j) were synthesized by Hantzsch method for pyridine synthesis. Treatment with chloroacetyl chloride produced N-(2-chloroacetyl)-3,5-(substituted)oxycarbonyl-1,4-dihydro-2,6-dimethyl-4-(substituted)pyridines (2a-e), which on further treatment with sulfanilamide resulted in 3,5-(substituted)oxycarbonyl-...

a series of n-substituted-2,4-thiazolidinedione derivatives (tzds) were prepared via n-alkylation of 2,4-tzd at position 3 using substituted benzyl halides. synthesized n-substituted-2,4-tzd was then substituted at position 5 with substituted aromatic aldehyde according to knoevenagel condensation method. structures of the compounds were elucidated using various spectral techniques viz. ir, 1hn...

In this study, multi component Hantzsch reaction was carried out between various  Aromatic Aldehyde with Dimedone,Ethyl acetateand ammonium acetate to produce polyhydroquinolinederivatives under solvent-free conditions at 110oC by a (Zinc oxide  nanocatalyst) as effective Lewis acid. The remarkable advantages offered by this method compared with other methods are a green catalyst, si...

An efficient and environmental-friendly synthetic route to 1,8-dioxodecahydroacridines derivatives have been developed via multi-component one-pot Hantzsch reaction of various aldehydes and ammonium acetate with 2 equivalents dimedone in the presence of Phosphorus pentoxide supported on aluminaas catalyst under solvent-free conditions. The present approach offersseveral advantages such as s...

An efficient and environmental-friendly synthetic route to 1,8-dioxodecahydroacridines derivatives have been developed via multi-component one-pot Hantzsch reaction of various aldehydes and ammonium acetate with 2 equivalents dimedone in the presence of Phosphorus pentoxide supported on aluminaas catalyst under solvent-free conditions. The present approach offersseveral advantages such as s...