Mohr's Salt Hexahydrate: A Novel,Cheap and Powerful Reagent for Green Synthesis of Biscoumarins on Water

A new and convenient method for the synthesis of biscoumarins based on the condensation of 4‐hydroxycoumarin and aromatic aldehydes in the presence of Mohr's salt hexahydrate (ferrous ammonium sulfate hexahydrate) as a novel catalyst on water is developed. This method has advantages such as the use of inexpensive and available reagent, avoidance of organic solvents, short reaction times, and high product yields.     

Facile,Regioselective and Green Synthesis of Ortho‐Nitrophenoles Using NaNO2, KHSO4

Certain phenols and naphtols were nitrated regioselectively with NaNO₂ in the presence of KHSO₄ at 50 °C in high yields.     

Facile Method for the Synthesis of Combinatorial Libraries of Benzimidazole, Benzothiazole, Benzoxazole, Perimidine and Quinazolinone

A highly yielding and fast method for the synthesis of heterocyclic compounds with trialkyl orthoformate using molecular sieve 3Å as a catalyst is described.     

Melamine Trisulfunic Acid: An Efficient and Recyclable Solid Acid Catalyst for the Synthesis of 4,4′‐(Arylmethylene)‐bis‐(1H‐pyrazol‐5‐ols)

Melamine trisulfunic acid is employed as a recyclable catalyst for the condensation reaction of aromatic aldehydes with 3‐methyl‐l‐phenyl‐2‐pyrazolin‐5‐one. This condensation reaction was performed in ethanol under refluxing conditions giving 4,4′‐(arylmethylene)‐bis‐(3‐methyl‐1‐phenyl‐1H‐pyrazol‐5‐ols) in 80‐96% yields.     

Novel One-Pot Synthesis of New Oxindole Derivatives Catalyzed by PTSA

The one-pot synthesis of spirooxindoles via three-component reaction of urea, isatin, and 1,3-dicarbonyl compounds in the presence of a catalytic amount of p-toluenesulfonic acid in acetonitrile has been carried out.

Efficient iodination of aromatic compounds using potassium ferrate supported on montmorillonite

Potassium ferrate impregnated on montmorillonite is a mild,cheap,and non-toxic reagent for the iodination of phenols, including naphthol,aromatic amines,and heterocyclic substrates in fair to excellent yields by a simple isolation procedure.