Ultrasound-assisted three-component synthesis of 3-(5-amino-1H-pyrazol-4-yl)-3-(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl)indolin-2-ones in water

Indium(III) chloride was found to be an efficient catalyst for the synthesis of 3-(5-amino-1H-pyrazol-4-yl)-3-(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl)indolin-2-ones by one-pot, three-component reaction of dimedone, 1H-pyrazol-5-amines and isatins in water under ultrasonic irradiation. The advantages of this method are the use of a readily available catalyst, easy workup, excellent yields, and the use of water as a solvent that is considered to be relatively environmentally benign.     

Cobalt-catalyzed isocyanide insertion cyclization to dihydrobenzoimidazotriazins

We have developed an isocyanide insertion reaction for the synthesis of dihydrobenzo[4,5]imidazo[1,2-a][1,3,5]triazins and imidazol-quinoxaline-5-carboxamides utilizing cobalt catalyst. Cobalt-catalyzed system is inexpensive and more acceptable from industrial point of view.     

TETRABUTYLAMMONIUM HYDROGEN SULFATE: AN EFFICIENT CATALYST FOR THE SYNTHESIS OF 3,4-DIHYDROPYRIMIDIN-2(1H)-ONES UNDER SOLVENT-FREE CONDITIONS

Tetrabutylammonium hydrogen sulfate (TBAHS) as[3pc] a solid protic acid and phase-transfer reagent catalyzed the three-component condensation reactions of aldehydes, 1,3-dicarbonyl compounds, and urea or thiourea under solvent-free conditions leading to 3,4-dihydropyrimidin-2(1H)-ones in high yields at 80°C.     

Simple and Efficient Synthesis of 1,3-Dithioles with Pyrimidinylidene or Pyrazolylidene Substituents

Abstract

2-Pyrimidinylidene-1,3-dithioles or 2-pyrazolylidene-1,3-dithioles are prepared by a three-component condensation reaction of pyrimidine-tetraone or 1H-pyrazole-4,5-dione, carbon disulfide, and dialkyl acetylendicarboxylates in the presence of tributylphosphine.

GRAPHICAL ABSTRACT      

A novel three-component method for the synthesis of triazolo[1,2-a]indazole-triones

An efficient synthesis of triazolo[1,2-a]indazole-1,3,8-trione derivatives based on the three-component condensation of urazole, dimedone and aromatic aldehydes under solvent-free conditions is described.     

Reaction of phthalhydrazide and acetylenedicarboxylates in the presence of N-heterocycles: an efficient synthesis of phthalazine derivatives

Some new phthalazine derivatives were prepared by reaction of phthalhydrazide and dialkyl acetylenedicarboxylates in the presence of N-heterocycles.