Silica-bonded n-propyldiethylenetriamine sulfamic acid (SBPDSA) was found as an efficient solid acid for the synthesis of coumarins. Coumarin derivatives were obtained via the Pechmann condensation reaction of phenols and β-keto-esters at 80 oC under solvent-free conditions. Also, biscoumarins were obtained via the condensation of aldehydes and 4-hydroxycoumarin in water at reflux conditions. T...

silica sulfuric acid is employed as solid acid catalyst for the clean and less hazardousprotection of carbonyl compounds as 2,4-dinitrophenylhydrazone under solvent-free conditions.

Bamboo is one of the important biopolymers which is used in chemistry. In this work, for the first time, a solid acid catalyst from bamboo was prepared from the reaction of sawdust bamboo and chlorosulfonic acid. Relevant properties of catalyst were investigated by FT-IR, XRD, SEM and TGA. The sulfonated bamboo (bamboo-SO3H) with several acid functional groups was utilized as highly ...

In the past few years multi component reactions have captured the attention of synthetic chemists as they provide  easy  access  to diverse  complex  organic molecules through  carbon -  carbon   and  carbon - heteroatom  bond  formations  in tandem manner with simple easy  to carry out  reaction  conditions in short  time. 1,8-dioxo-octahydroxanthene is a significant class of oxygen containing...

In this research, the chemical recycling of terephthalic acid from PET waste by using nano Fe3O4@Py-APTS as solid support was reported. The performance of organically modified nano magnetic was examined in detail and the results were compared with unsupported reactions as the model. By using the solid support, the required time for complete glycolysis, consumption of solvent and catalyst, decre...

Silica sulfuric acid is employed as solid acid catalyst for the clean and less hazardousprotection of carbonyl compounds as 2,4-dinitrophenylhydrazone under solvent-free conditions.

This paper revisits the cultural stereotype of a sharp binary division between “summer” and “winter” temporalities in an island town Croatia (Hvar). It highlights existence parallel competing that generate heterogeneous social individual rhythms. The overarching rhythm summer tourism, which divides year into (roughly May October) November April), conceals other temporalities, both sense how loc...