Green One Pot Solvent-Free Synthesis of Pyrano[2,3-c]-Pyrazoles and Pyrazolo[1,5-a]Pyrimidines

Green one pot solvent-free synthesis of pyrano[2,3-c]-pyrazoles and pyrazolo[1,5-a]pyrimidines.

Pyrano[2,3-c]pyrazoles are obtained via mixing ethyl acetoacetate, hydrazine hydrate, aldehydes or ketones and malononitrile in the absence of solvent. These same products were also obtained by reacting arylidenemalononitriles 3 with 3-methyl-2-pyrazolin-5-ones. NOE difference experiments confirmed that these products exist solely in the 2H form. Similar treatments of 3-amino-2-pyrazolin-5-one ...

Solvent-Free Green and Efficient One-Pot Synthesis of Dihydropyrano[3,2-c]chromene Derivatives

A rapid, clean, and highly efficient method for synthesis of dihydropyrano[3,2-c]chromene derivatives by one-pot, three-component condensation of aromatic aldehydes, malononitrile, and 4-hydroxycoumarin using DABCO as catalyst in solvent-free neat conditions is described. The present method has the advantages of mild reaction conditions, short reaction times, easy isolation of products, and exc...

CuCl2 Catalyzed Solvent-free One Pot Synthesis of Dihydropyrimidinones

Green and Efficient One-Pot Synthesis of 2-Amino-3-phenylsulphonyl-4H-chromenes under Solvent-Free Conditions

A green and convenient method for the synthesis of 2-amino-3-phenylsulphonyl-4H-chromenes by a one-pot three-component condensation of 1-naphthol, phenylsulphonylacetonitrile and aromatic aldehydes under solvent-free conditions using potassium phosphate tribasic trihydrate as an efficient catalyst is described. The reaction of 1-naphthol with phenylsulphonylacetonitrile and various aromatic...

One-pot synthesis of Benzimidazole derivatives under microwave Irradiation and solvent-free condition

A simple, fast, efficient and environmentally friendly method for synthesis of benzimidazole and its 2-alkyl, aryl and heteroaryl substituted derivatives was developed using zeolite HY. Two component cyclolcondensation of 1,2-phenylenediamine (o-phenylenediamine) and commercially available carboxylic acids catalyzed by zeolite HY without any solvent, under microwave irradiation led to formation...