1‐Arylsulfonyl‐2‐styrylsulfonylthenes — source for a new class of bis heterocycles

New and novel sulfone linked bis heterocycles_ bis pyrroles and pyrrolyl pyrazolines are prepared from 1‐arylsulfonyl‐2‐styrylsulfonylethenes by 1,3‐dipolar cycloaddition methodology.     

Reactions of 4‐dimethylamino‐3‐quinolinyl sulfides with nitrating mixture and transamination of 4‐dimethylamino‐3‐methylsulfinyl‐6‐nitroquinoline

4‐Amino‐3‐quinolinyl sulfides 4d‐e and 7a‐c were prepared by amination of 4‐chloro‐3‐quinolinyl sulfides 4c or 1c , respectively, in methanol (140‐160 °C) or in boiling phenol with yields up to 95 %. Reaction of 4‐dimethylamino‐3‐quinolinyl sulfides 7c and 4e with nitrating mixture proceeded simultanously as oxidation of the methylthio group to the methylsulfinyl one and as C6‐nitration to form 6‐nitro‐β‐quinolinyl sulfoxides 9c or 10b , respectively. 4‐Dimethylamino‐3‐methylsulfinyl‐6‐nitroquinoline 9c underwent acid catalysed transamination when reacting with primary aliphatic amines and ammonia.     

Convenient way to 5‐substituted 4‐amino‐2,3‐dihydro‐4H‐1,2,4‐triazole‐3‐thiones

Various 4‐amino‐2,3‐dihydro‐4H‐triazoles with aromatic, aliphatic and heterocyclic substituents at the C(5) position were synthesized from corresponding esters and thiocarbohydrazide. This method allows the synthesis these heterocycles in a short time and at reduced expenses.     

Synthetic and spectroscopic studies of some new 2‐[1‐aryl‐4{4‐methoxyphenyl}‐6‐thioxo‐1,6‐dihydro‐1,3,5‐triazinyl]amino/hydrazonothiazolidin‐4‐ones

A series of 4‐thiazolidinones having triazinethione moieties have been synthesized by the systematic chemical modification of S‐benzylmercapto‐1‐aryl‐4‐(4‐methoxyphenyl)‐1,6‐dihydro‐1,3,5‐triazine‐6‐thione.     

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.     

Reactions of aroylthioureas with acetylenic esters and dibenzoyl ethylene. Selectivity towards the formation of new 1,3‐thiazines

A series of 1,3‐thiazines has been synthesized by the reactions of N‐aroylsubstituted thioureas with ethyl propiolate, dimethyl but‐2‐ynedioate and (E)‐1,4‐diphenyl‐but‐2‐ene‐1,4‐dione. The reaction of antipyrinylphenyl thiourea with π‐deficient acetylenic reagents did not afford the corresponding 1,3‐thiazines, whereas pyrrolo‐pyrazolopyrimidines were obtained.     

A convenient synthesis of 5‐alkylthio‐3,4‐diarylisoxazoles by palladium‐catalyzed coupling reactions

Palladium‐catalyzed coupling reaction was found effective for rapid access to pharmacologically interesting 3,4‐diarylisoxazoles derivatives as selective COX‐2 inhibitors. Thus, the coupling reaction between 5‐alkylthio‐3‐aryl‐4‐iodoisoxazoles and arylboronic acids afforded the target 5‐alkylthio‐3,4‐diarylisoxazoles in good yields.     

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.     

Synthesis,stereochemistry and adsorption studies of new spiranes and polyspiranes containing 1,2‐dithiolane units

The synthesis and stereochemistry of a series of new cyclic disulfides containing (poly)spirane 1,2‐dithiolane units are reported. Also included is a study of the self‐assembled monolayers (SAMs) of these compounds on a gold surface. The characteristics of the resultant SAMs were determined by IR spectroscopy using molecular mechanics calculations.     

Progress in the chemistry of 4‐ thiazolidinones

This review article includes a recent development in the chemistry of 4‐thiazolidinones. Structure, basicity, synthetic aspects, reactions, and applications were also reported.     

FeCI3‐promoted [3+3] cycloaddition: Efficient preparation of 1,2‐dihydro‐2‐oxo‐3‐pyridinecarboxylate and 1,2‐dihydro‐2‐oxo‐3‐pyridinecarboxamide derivatives

A facile approach was developed on assembly of the 2‐pyridone nucleus by ferric chloride promoted [3+3] cycloaddition in propionic acid. The tandem process involves cyclization of Michael adduct followed by aromatization. Thus, different substituted 1,2‐dihydro‐2‐oxo‐3‐pyridinecarboxylate and 1,2‐dihydro‐2‐oxo‐3‐pyridinecarboxamide derivatives were prepared in good yields from various enones with malonamic ester and malonamide, respectively     

Chemo,stereo, and regioselective addition of α‐(2‐methoxyaryl)‐N‐aryl nitrones to diarylidineacetone: Synthesis of novel isoxazolidines

A new set of 2,3,4,5‐tetrasubstituted isoxazolidines with an α,β‐unsaturated carbonyl function at position 4 has been synthesized. The multicomponent approach and microwave irradiation protocol have also been investigated for the above synthesis.     

Synthesis and anti‐HIV‐1 evaluation of 1,5‐disubstituted pyrimidine‐2,4‐diones

1,5‐Disubstituted pyrimidine‐2,4‐diones were synthesized by fusion of 5‐bromouracil with an aniline derivative followed by coupling with benzyl halide whereas the opposite synthesis sequence failed. Also 4,6‐dichloro‐N,N,5‐trimethylpyrimidin‐2‐amine was treated with phenols. The products were tested for their activity against HIV‐1.     

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.     

Convenient preparations of 2‐alkyl‐5‐oxopyrrolidine‐3‐carboxylic acids

Reduction of the Michael addition products of anions of nitro compounds to dimethyl maleate led to the spontaneous formation of the respective 2‐alkyl‐5‐oxopyrrolidine‐3‐carboxylic acid methyl esters. Conventional hydrolysis of the later gave the desired compounds.     

Synthesis and DNA‐binding properties of 1,10‐phenanthroline analogues as intercalating‐crosslinkers

We synthesized a series of bis(bromomethyl)‐1,10‐phenanthrolines as novel anticancer lead compounds and examined their DNA‐binding properties. 5,6‐Bis(bromomethyl)‐1,10‐phenanthroline showed DNA intercalating activity and DNA crosslinking activity, furthermore it is stable in aqueous solution.     

Synthesis and antimicrobial activity of some new N‐(substituted phenyl)‐N′‐[2,3‐dihydro‐2‐oxido‐3‐(4′‐fluorophenyl)‐1H‐(1,3,2)benzoxazaphosphorin 2‐yl]ureas

Substituted benzoxazaphosphorin 2‐yl ureas were synthesized by reacting 2‐(4‐fluoro‐phenylamino)‐methylphenol (4) with different carbamidophosphoric acid dichlorides (3) in the presence of triethylamine in dry toluene at 45‐50 °C and characterized by spectral data. These compounds were found to possess good antimicrobial activity.