Abstract A highly efficient and catalyst-free protocol is reported for the synthesis of quinoxalines via classical cyclocondensation reaction between aryldiamines dicarbonyl compounds. Remarkably simple green conditions employing methanol as solvent afforded medium to excellent yield after only one-minute time at ambient temperature. The allow least 10 gram scale should be a preferred starting ...

A new series of (benzofuran-2-yl)-1-phenyl-1H-pyrazol-4-yl) pyrimidine derivatives were synthesized from 3-(benzofuran-2-yl)-1-phenyl-1H-pyrazol-4-carbaldehyde (1) through different routes of cyclocondensation reactions. Condensation of 1 with active methylene compounds afforded compounds 2-8. The cyclization of 2 with chloroacetic acid, ortho substituted benzoic acid and/or ethanolamine gave c...

The cyclocondensation reaction between rigid, electron-rich aromatic diamines and 1,1'-bis(2,4-dinitrophenyl)-4,4'-bipyridinium (Zincke) salts has been harnessed to produce a series of conjugated oligomers containing up to twelve aromatic/heterocyclic residues. These oligomers exhibit discrete, multiple redox processes accompanied by dramatic changes in electronic absorption spectra.

Unsymmetrical dispiro- and spirotetraoxanes have been designed and synthesized via acid-catalyzed cyclocondensation of bis(hydroperoxides) with ketones. Incorporation of water-soluble and polar functionalities, via reductive amination and amide bond formation, produces several analogues with low nanomolar in vitro antimalarial activity. Several analogues display an unprecedented level of oral a...

The one-step cyclocondensation of substituted isoflavones with cyanothioacetamide in the presence of sodium hydroxide gave an array of 3-cyano-5,6-diaryl pyridine-2(1H)-thiones in good yields. The procedure involves base-mediated ring opening of the isoflavones and subsequent Knoevenagel condensation between the 1,3-dicarbonyl intermediate generated from the isoflavones and cyanothioacetamide, ...

We discovered a novel organocatalysed multicomponent domino Knoevenagel-aza-Michael-cyclocondensation reaction leading to an unprecedented straightforward synthesis of 1,5-diazabicyclo[3.3.0]octane-2,6-diones. The specific capability of the (DHQ)2PHAL organocatalyst in this process was also highlighted to eventually furnish the corresponding bicyclopyrazolidinones with up to 96 : 4 er.

A facile synthesis of potential acetylcholinesterase (AChE) inhibitors, the tacrine analogues 3a-p, has been accomplished by direct cyclocondensation of 1-aryl-4-cyano-5-aminopyrazole with β-ketoesters using tin(IV) chloride as catalyst. The structures of all the compounds have been confirmed by IR, ¹H- and ¹³C-NMR.

Large chiral triangular macrocycles having three salen ligand sites were obtained by cyclocondensation of trans-1,2-diaminocyclohexane with linearly connected bis-salicylaldehydes. Structures of the ligands and their titanium(IV) or zinc(II) complexes have been characterized by means of spectroscopic (CD) and computational (DFT) methods.

spiro-4- thiazolidinones have been synthesized by the cyclocondensation of phthalazinyl hydrazones with cyclic ketones and substituted mercapto acetic acids. compounds were screened for their antibacterial, antifungal and antihypertensive activity. the combined elemental analyses and spectroscopic data prove the authenticity of the synthesized compounds