Reactions of carbamoylated amino enones with 3-substituted chromones for the preparation of 2-pyridones and chromeno[4,3-b]pyridine-2,5-diones

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Self-condensation of 2-(ethoxalylmethyl)chromones into new derivatives of isotetronic acid

2-(Ethoxalylmethyl)chromones undergo dimerization to dichromonyl derivatives of isotetronic acid in 62–89% yields on refluxing with 2,3-diaminopyridine in ethanol for 1–2 h.     

Synthesis and conformational analysis of N-aryl-N-(3-thienyl)acetamides

The cis-trans conformational equilibrium of amides is of interest because it can be used to control functional activity. Here, we designed and synthesized a series of N-(3-thienyl)amides in order to study the factors affecting their conformational equilibrium. NMR studies showed that the major conformer of N-methyl-N-(3-thienyl)amide in solution is the E-form (cis form), as is the case for N-methylacetamide. For N-aryl-N-(3-thienyl)amides bearing an N-phenyl moiety, the major conformers differ depending on not only the relative π-electron density of the N-aryl moiety, but also its size. X-ray analysis showed that their solid-state conformational preferences were similar to those in solution.     

Synthesis of 4H-1,3-benzoxazin-4-ones from 2,2-diazidobenzofuran-3(2H)-ones

Benzoxazine derivatives are useful building blocks and display various biological activities. We serendipitously discovered and subsequently developed a new one pot method for the synthesis of 2-(dimethyl amino)/2-morpholino/2- (piperidin-1-yl)-4H-benzo[e][1,3]oxazin-4-ones from corresponding substituted 2,2-diazidobenzofuran 3(2H) - ones and N-formyl dimethyl amine (DMF)/N-formylmorpholine/N-formylpiperidine using m-CPBA at 100?°C in moderate to good yields. We also demonstrated the utility of 4H-benzoxazines for the synthesis of other medicinally important compounds such as 2-hydroxyphenyl substituted 1,2,4-triazoles, unsymmetrical 1,3,5-triazines, and 1,2,4-oxadiazoles.     

Synthesis and photophysical studies of novel 4-aryl substituted 2-phenyl-, 2-(fluoren-2-yl)- and 2-cymantrenylquinazolines

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Synthesis and properties of 1,3-diphenyl-5-(benzothiazol-2-yl)-6-R-verdazyls

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Synthesis and photophysical studies of novel 2-[5-(4-diethylaminophenyl)thiophen-2-yl]quinazoline derivatives

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Deprotonation of 1,1′-methylenebis[4-tert-butyl-2-(diphenylphosphino)-benzene] and its analogues: synthesis and crystal structure of {5-But-2-[4-But-2-(Ph2P)C6H3(Ph)CH]C6H3P(Ph)K(OEt2)}2

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The reaction of 4-(1,3,2-benzodioxaphosphol-2-yloxy)-3-tert-butylpent-4-en-2-one with hexafluoroacetone

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3-(4-Phosphoryl-4-methyl-2-oxopentyl)-3-hydroxyindolin-2-ones,the first phosphorus analogues of natural convolutamydines

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Synthesis of (R)- and (S)-isomers of 2-methylspermidine

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Synthesis of 1-(hydroxyaryl)furo[3,4-c]pyridines from 1-amino(alkoxy)furo[3,4-c]pyridines and (poly)phenols

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A convenient synthesis of copper(II) bis[5-(pyridin-2-yl-methylidene)-2-thiohydantoin] complexes

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Synthesis,structure and magnetic properties of the dinuclear complex [1,3-C6H4{NC(Ph)N(SiMe3)}2]3Dy2 coordinated by ansa-bis(amidinate) ligands with a m-phenylene linker

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Copper(I) halide-promoted formation of 3-acyl-5-halopyridine moiety from NH-2-(2-acylethynyl)pyrroles and propargylamine

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Reversible intramolecular Dieckmann-type condensation of 2-(2-hydroxymethyl-5,5,6-trimethoxytetrahydropyran-3-ylcarbonyl)-cyclopentanone: an alternative access to medium-sized lactones

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Synthesis of new pharmacologically oriented heterocyclic ensembles, [2-(1H-pyrazol-1-yl)thiazol-4-yl]furoxans

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Synthesis and biological evaluation of new N-substituted 4-(arylmethoxy)piperidines as dopamine transporter inhibitors

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Synthesis of enantiomerically pure 2-(N-aryl,N-alkyl-aminomethyl)aziridines: a new class of ligands for highly enantioselective asymmetric synthesis

A simple and effective synthesis of enantiomerically pure 2-(N-aryl-, N-alkyl-aminomethyl)aziridines from (2S)-N-tritylaziridine-2-carboxylic acid methyl ester has been developed. Treating of this key ester with several primary and secondary amines in the presence of AlMe₃ provided the corresponding chiral N-trityl-2-carboxamides, and their reduction performed with different reagents resulted in the formation of the expected 2-(aminomethyl)aziridines. The choice of reaction conditions allows to either keep or leave the trityl substituent in the product. Such 2-(aminoalkyl)aziridines have shown very high catalytic efficiency in the asymmetric arylation of aldehydes and in other testing asymmetric reactions. On the other hand, homochiral N-trityl-2-carboxamides are interesting building blocks for the synthesis of various biologically active compounds.     

Synthesis of N-aryl-hexaoxazadispiroalkanes using lanthanide catalysts

An efficient method was developed for the synthesis of N-arylhexaoxazadispiroalkanes by the ring transformation of heptaoxadispiroalkanes with arylamines in the presence of lanthanide salts as catalysts.