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A series of 2-hydroxy-2-(4-oxo-1,2-diaryl-4,5,6,7-tetrahydro-1 H -3-indolyl)-2-cyanoacetamides have been synthesized through selective C H oxidation of active methylene carbon of cyanoacetamide derivatives using tert -butyl hydroperoxide as oxidant and ferric chloride as radical initiator. In this reaction the tert -butyl oxo radical abstracts hydrogen from the active methylene group of 2-pyrolyl-2-cyanoacetamides to generate a stable captodative radical intermediate. Then recombination of this radical intermediate with tert -butyl oxo radical followed by acid catalysed thermal elimination of the tert -butyl group produces the quaternary hydroxyl cyanoacetamide derivatives in good yield. [ABSTRACT FROM AUTHOR]

A series of biologically important isoindolone embedded heterocycles such as tetracyclic 2,4-diamino-5-aryl-10-oxo-10H-1,10a-diazaindeno[2,1-a]indene-3-carbonitriles and tricyclic 1-aryl-3,5-dioxo-1H-imidazo-[3,4-b]isoindoles have been synthesized from an easily derived common intermediate, 3-(2'-hydroxyaroyl)-2,3-dihydroisoindol-1-ones. The significant advantages of the present methodologies are the use of simple and easily available starting materials and reagents, operational simplicity, and good yields of the products with high atom-economy. [ABSTRACT FROM AUTHOR]

Abstract: An easy and inexpensive method has been developed to access 1,2-disubstituted benzimidazoles following a one-pot sequential coupling/reduction/cyclization process under metal-free neutral conditions. [Copyright &y& Elsevier]

A new and efficient procedure has been developed for the synthesis of a series of pyrazole-fused isocoumarins from easily available ninhydrin and arylhydrazones. In this synthesis the condensations of ninhydrin and arylhydrazones are carried out under solvent free conditions employing magnetically separable Fe 3 O 4 @SiO 2 -SO 3 H nanoparticles as solid acid support. Some members of pyrazole-fused isocoumarins are known to bind to a GABA receptor. [ABSTRACT FROM AUTHOR]

A useful and convenient methodology has been developed for synthesis of mono N-arylated aliphatic 1,2- and 1,3-diamines and amino alcohols. A highly efficient and renewable heterogeneous chitosan supported copper(II) catalyst has been employed for the C–N cross coupling between aryl halides and aliphatic diamines/amino alcohols. The main advantages of this reaction are the high yields of the products, reduced reaction time, convenient work up procedure, renewability of the catalyst, and less metal contamination of the products. All these factors make the present C–N cross coupling reaction economical, green, and sustainable. [ABSTRACT FROM AUTHOR]

Abstract: A highly efficient protocol for the library synthesis of biologically important 3H,3′H-spiro[benzofuran-2,1′isobenzofuran]-3,3′-diones has been developed by employing silica sulfuric acid (SSA) as solid acid support under solvent-free condition. The dual characteristics of SSA, as an activating agent as well as oxidizing agent, have been well exposed in these syntheses. The intrinsic advantages of the methodology are the use of solvent-free reaction condition without using any toxic reagents or metal catalyst, operational simplicity, recyclability of the solid support, good availability of the starting materials, and excellent yields which make the method attractive, economic, and ‘benign by design’. [Copyright &y& Elsevier]

Abstract: The synthesis of a series of biologically important ninhydrin and isatin based hydrazones has been carried out by refluxing easily synthesized novel N′-(chloro-aryl-methylene)-tert-butylcarbazates with ninhydrin and isatins in the presence of PEG-OSO3H as catalyst in water medium. The dual characteristic of PEG-OSO3H as a Brønsted acid as well as a phase-transfer catalyst is successfully exploited in this synthesis. Reduced reaction time, operational simplicity, excellent yields of the products with high purity, and more importantly, easy recoverability, and reusability of the homogeneous polymeric catalyst make the reaction an attractive, economic, and sustainable green synthetic methodology. [Copyright &y& Elsevier]

Abstract: Microwave irradiation of a solid mixture of aryl 1,2-diketones, l-proline, and ammonium acetate (excess) for 15min produces 2,3-diaryl-6,7-dihydro-5H-pyrrolo[1,2-a]imidazoles in moderate yields. Mechanistically this one-pot three-component reaction generates pyrroloimidazoles through the intramolecular cyclization of 1,2-diimine intermediates derived from the condensation of aryl 1,2-diketones, l-proline, and ammonia in 1:1:1 molar proportion. The significant advantages of this methodology are cost-effectiveness, operational simplicity, and reduced reaction time. [Copyright &y& Elsevier]

Abstract: The synthesis of biologically important 5-aryl-3H-[1,3,4]oxadiazol-2-ones has been carried out by heating the easily synthesized N′-(chloro-aryl-methylene)-tert-butylcarbazates on basic alumina surface under solvent-free condition. The dual characteristic of basic alumina as a solid support as well as a nucleophile is successfully exploited in these reactions. The method provides special attributions such as reduced reaction times, easier work-up procedures, and good to excellent yields as well as increased purity of products and most importantly environmentally friendly protocols. The basic alumina is easily recovered and utilized for further reactions several times without serious loss of activity. [Copyright &y& Elsevier]

Abstract: The refluxing of a mixture of ethylcyanoacetate, aromatic aldehydes, and primary monoamines in ethanol produces highly substituted 2-amino-6-pyridones such as 2-amino-1-(alkyl)-5-cyano-6-oxo-4-(aryl)-1,6-dihydropyridine-3-ethylcarboxylates in one-pot. On the other hand the refluxing of a mixture of ethylcyanoacetate, aromatic aldehydes, and primary diamines (1,2-ethylenediamine/1,3-propylenediamine) in ethanol furnishes symmetrical zwitterionic 2-pyridones such as 1-(2-amino-ethyl/3-amino-propyl)-6-hydroxy-2-oxo-4-(aryl)-1,2-dihydropyridine-3,5-dicarbonitriles. The result shows that primary diamines and monoamines react differently in the reactions, which provides new mechanistic insight into the regioselective synthesis of these biologically important compounds. [Copyright &y& Elsevier]

Abstract: A simple and efficient procedure has been developed for the synthesis of substituted pyrrole-fused isocoumarins from easily available ninhydrin. The cyclic hemiaminal dihydroxy-indenopyrroles, the adducts of ninhydrin with enamines of acetylacetone, give pyrrole-fused isocoumarins upon heating in acidic medium. The process constitutes an interesting acid-catalyzed rearrangement to eight-membered lactams followed by intramolecular cyclization involving the amino and keto groups. [Copyright &y& Elsevier]

Abstract: A simple one-pot procedure for the conversion of 2-hydroxy-2-(2′-hydroxy-aryl)-1,3-indanediones to 4-substituted benzoxazinones has been developed. The process constitutes an interesting acid-catalyzed rearrangement followed by condensation with hydroxylamine. [Copyright &y& Elsevier]

Abstract: An efficient methodology for the synthesis of 3H,3′H-spiro[benzofuran-2,1′-isoindole]-3,3′-diones has been developed where monobromomalononitrile (MBM) has been employed as a non-hazardous brominating agent under ambient reaction condition. The intrinsic advantages of the methodology are the utilization of simple and easily available starting materials and non-toxic reagents, operational simplicity, and good yields of the products with high atom-economy. [Copyright &y& Elsevier]

Abstract: Biologically important phthalazinones, 2,3-benzoxazin-1-ones and isoindolinones have been synthesized from easily available ninhydrin in good yields. The appropriate ninhydrin adducts 2,2,-diaryl-1,3-indanediones and 3-(diarylmethylene)isobenzofuranones were treated with various nucleophiles like hydrazine hydrate, hydroxylamine, and phenylhydrazin to accomplish the heterocycles. The synthesized compounds were assayed for their antibacterial activity and showed significant activity against both the selected Gram positive and Gram negative bacteria, suggesting possible scope of using as antimicrobials. [Copyright &y& Elsevier]