Mn(III) acetate mediated diasteroselective [3+2] oxidative addition of 1,3‐dicarbonyl compounds with chalcones

A diastereoselective synthesis of 4,5‐dihydrofurans by oxidative addition of 1,3‐dicarbonyl compounds with chalcones mediated by Mn(OAc)₃ in moderate to good yields is reported.     

N‐alkylated 3,5‐bis(arylidene)‐4‐piperidones. Synthetic approaches,X‐ray structure and anticancer activity

In a search for cytotoxic fluorescent materials a series of N‐alkylated and N,N‐dialkylated 3,5‐bis(arylidene)piperidones was synthesized. Alkylation of 3,5‐bis(arylidene)‐4‐piperidone afforded quaternary salts only while condensation of N‐alkyl‐4‐piperidones with substituted benzaldehydes was a convenient route to the corresponding N‐alkylated compounds. Compounds and their pharmaceutically acceptable salts demonstrated high activity against resistant human lung carcinoma cell line A549 with IC₅₀ values in the range of 0.3‐6.5 μM.     

An efficient and expeditious microwave‐assisted synthesis of quinoxaline derivatives via nucleophilic heteroaromatic substitution

A series of 2‐substituted quinoxaline derivatives including five novel compounds have been successfully synthesized from 2‐chloroquinoxaline using microwave methodology. The yields of the quinoxalines synthesized through this method, were an improvement over the thermal methods usually employed.     

Photocyclisations of some 3‐alkoxy‐2‐thienylchromones

Photoreorganisations of some 3‐allyloxy‐2‐thienylchromones have been described. The photoreactions are initiated through the intramolecular H‐abstraction to provide angular tetracyclic compounds. These chromones yield good chemical efficiency due to the involvement of highly stabilized allylic 1,4‐biradicals.     

Solvent‐free one‐pot approach for synthesis of substituted 2‐aminochromenes

A solvent‐free one‐pot approach for the preparation of 2‐aminochromenes in the presence of NaHCO₃ by grinding was described. Its advantages are easy work‐up, mild reaction condition, high yield and environmental compatibility.     

Modern Supramolecular Gold Chemistry.Gold‐Metal Interactions and Applications. Edited by A. Laguna.

Wiley‐VCH, Weinheim 2008. 505 pp., hardcover € 159.00.—ISBN 978‐352732095

     

Synthesis of nitropyrazolidines

Synthesis of 1, 2‐diacetyl‐4, 4‐dinitropyrazolidine 1 and results of further nitration of the 1,2‐diacetyl‐4,4‐dinitropyrazolidine are described.     

Phenacylsulfonylacetic acid methyl ester‐synthon for 1,2,3‐selena/thiadiazoles and 2H‐diazaphospholes

A new class of 1,2,3‐selena/thiadiazoles and 2H‐diazaphospholes were synthesized by exploiting α‐ketomethylene group in phenacylsulfonylacetic acid methyl ester.     

1,3‐Dipolar cycloadditions: Investigation of cycloadditions of c‐aryl‐n‐(4‐chlorophenyl) nitrones to n‐cinnamoyl piperidines

Investigation of cycloadditions of C‐aryl‐N‐(4‐chlorophenyl)nitrones to N‐cinnamoyl piperidines was carried out. Two diastereoisomeric and one regioisomeric cycloadducts, and in some cases ring‐opened compounds were characterized by spectroscopic and X‐ray data. Molecular modelling was carried out for conformational studies.     

Novel piperidine nitroxide derivatives: Synthesis,electrochemical and antioxidative evaluation

Novel paramagnetic materials ( 3a , 3b , 4a and 4b ) based on heterocyclic dyes ( 2a and 2b ) and one stable nitroxide radical (4‐NH₂‐TEMPO) were synthesized. EI‐MS, elemental analysis and FT‐IR spectral data confirmed the structures of the newly synthesized compounds. In addition, the cyclic voltammetry, the antioxidant activity and reactive oxygen species (ROS) scavenging properties of these compounds are discussed in this paper.     

A convenient synthesis of novel 1,3,4‐triaryl‐3,4‐dihydropyrimidin‐2(1H)‐ones by cyclization of aromatic isocyanates with β‐arylamino‐1‐phenylpropan‐1‐ones

A simple one‐step method for preparation of novel 1,3,4‐triaryl‐3,4‐dihydropyrimidin‐2(1H)‐ones has been developed by reaction of aromatic isocyanates with β‐arylamino‐1‐phenylpropan‐1‐ones in refluxing toluene in the presence of KHSO₄ and HCl.     

Efficient synthesis of 6‐aryl‐2‐chloronicotinic acids via pd catalyzed regioselective suzuki coupling of 2,6‐dichloronicotinic acid

A regioselective Suzuki coupling of 2,6‐dichloronicotinic acid with aryl boronic acids to synthesize 6‐aryl‐2‐chloronicotinic acids is described. Regioselectivity was achieved in aqueous dioxane using the routinely used catalyst Pd(PPh₃)₄.     

Synthesis of new imidazole derivatives

The derivatives of 1‐propyl‐ and 1‐butyl‐ of 2‐methyl‐5‐nitroimidazole containing phenylpiperazine, m‐chloro‐ and o‐methoxyphenylpiperazine attached at the end of alkyl chain were synthesed. For the obtained new compounds, the biological activity was predicted using the computer program PASS.     

Simple and efficient one‐pot synthesis of 3,4‐dihydro‐2‐pyridones via solid‐supported Bi(III)nitrate catalyzed double michael addition‐azaannulation

4‐Aryl‐5‐carboethoxy‐6‐methyl‐2,3‐dihydro‐2‐pyridones were obtained, in high yield, by heating ternary mixtures of appropriate aldehydes, ethylacetoacetate and compounds possessing NH₂‐C=X functionality, in presence of immobilized Bi(III)nitrate and co‐catalyst Zn(II)chloride, under solventless conditions. The reaction proceeds smoothly at 140±5°C and seems to involve double Michael addition‐azaannulation.     

Synthesis and biological properties of 1,8‐naphthalimidebutylamines. Serotonin 5‐HT1A and 5‐HT7 binding data and pass‐assisted search

Syntheses of the N‐substituted butyl derivatives of 1,8‐naphthalimide ( 1‐8 ), containing various arylpiperazines, tetrahydroisoquinoline and methylhomopiperazine moieties attached at 4‐position of the butyl chain have been described. Biological activities were evaluated in vitro for their ability to bind to serotonin 5‐HT_1A and 5‐HT₇ receptors. Due to the structural similarity of derivatives 1‐8 to psychotropic agents, the pharmacological properties of target compounds were predicted using PASS program.     

Regioselective cyclodehydration of ortho‐hydroxy acetyl aryloxyketones to benzofuran

ortho‐Hydroxy acetyl benzofuran derivatives have been synthesized in a regioselective cyclodehydration of aryloxyketones obtained from β‐resacetophenone and α‐halo ketones.     

An efficient and high yielding protocol for the synthesis of substituted dihydropyrimidin‐2(1h)‐ones and spiro‐fused heterocycles by involving tandem reactions

A simple and efficient method has been developed for the synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones by a one‐pot three component cyclocondensation reaction of alkyl acetoacetates, aldehyde, and urea in the presence of a catalytic amount of the reusable catalyst zinc per chlorate hexahydrate, Zn(ClO₄)₂.6H₂O (10 mol %) the scope of this protocol is utilized for the synthesis of mitotic Kinesin EG5 inhibitor monastrol and new class of fused heterobicyclic compounds in high yields.     

Synthesis and antimalarial activity of 7‐benzylamino‐1‐isoquinolinamines

Computer modelling suggests that 7‐benzylamino‐1‐isoquinolinamines should mediate antimalarial effects by a mechanism distinct from that employed by existing antimalarial drugs. A series of these compounds was prepared in seven synthetic steps, via reductive amination of 1,7‐isoquinolinediamine. In vitro efficacy testing of the novel compounds against Plasmodium falciparum revealed them to be potent antimalarial agents.