Heterocyclic Communications 

About: Heterocyclic Communications is an academic journal published by De Gruyter. The journal publishes majorly in the area(s): Aryl & One-pot synthesis. It has an ISSN identifier of 0793-0283. It is also open access. Over the lifetime, 1794 publications have been published receiving 9052 citations. The journal is also known as: HC & an international journal in heterocyclic chemistry.

SYNTHESIS OF SOME SCHIFF BASES,THIAZOLIDINONES AND AZETIDINONES DERIVED FROM 2,6-DIAMINOBENZO[1,2-d:4,5-d'] BISTHIAZOLE AND THEIR ANTICANCER ACTIVITIES

Abstract: New Thiazolidinones and Azetidinones were synthesized from Schiff Base derivatives which were prepared by the reaction of 2,6-Diaminobenzo[l,2-d:4,5-d'] bisthiazole and various aldehydes.The compounds were established on the basis of elemental analysis and spectral data.

The isolation and structures of five new alkaloids, norzoanthamine, oxyzoanth amine, norzoanthaminone, cyclozoanthamine and epinorzoanthamine

Abstract: Norzoanthamine, oxyzoanthamine, norzoanthaminone, cyc lozoanthamine and e p i n o r z o a n t h a m i n e have been isolated from a colonial zoanthid Zoanthus sp. collected in the Amami Islands of Japan and their structures have been elucidated by detailed spectroscopic analysis and X-ray crystallographic analysis. In our continuing search for physiologically active substances from marine organisms (1), we found five novel cytotoxic a lka lo ids , no rzoan thamine , o x y z o a n t h a m i n e , n o r z o a n t h a m i n o n e , cyc lozoan thamine and epinorzoanthamine from the genus Zoanthus on the Ayamaru coast of the Amami Islands. They inhibited growth of P388 murine leukemia cells with IC50 values of 24, 7.0, 1.0, 24 and 2.6 μg/ml1 respectively. Although a couple of zoanthamine derivatives possessing the unique heterocycles has been already reported (2), we wish to report herein the isolation and structures of newly isolated compounds of this series. The wet specimens (5.0 kg) which occurred as dense mat were minced by a Waring blender and extracted with ethanol. The ethanolic extract was filtered and concentrated in vacuo. The aqueous residue was partitioned between ethyl acetate and water, and the water layer was subsequently extracted twice with ethyl acetate. The lipid-soluble extracts were chromatographed on silica gel (eluted with chloroform containing methanol), followed to be separated by preparative TLC on S1O2 with acetonitri le, diethyl ether or ethyl acetate as solvent, giving zoanthamine 1 ( 6 . 3 X 10\" %) , norzoanthamine 2 as a colorless crystal [21 mg, 4.2 X 10\" %, mp. 282~285°C; [A]D 1.6° (c, 1.0, CHCI3)], oxyzoanthamine 3 [9.1 mg, 1.8 χ 1 0 \" 6 % , [

Synthesis and Antibacterial Activity of some Heterocyclic β-Enamino Ester Derivatives with 1,2,3-triazole

Abstract: Some new heterocyclic ß-enamino ester derivatives with v-triazole were preparaed, and their inhibiting effects on various bacteria were also investigated. Heterocyclic ß-enamino esters have been proved to be versatile synthons for the construction of manifold heterocondensed systems(l). Among them, heterocyclic ß-enamino containing 1,2,3triazole are of great interest because of their high biologocal activity and pharmacological property. For example, as potential medicinal agents(2), they are currently used in research field on virus(3), in minishinflammatory(5), and used for antishock,anesthesia(4), especially in antitumor and antimicrobial activity(6). We are interested in the design of new 1,2,3-triazole derivatives and their biological activities, and have prepared some heterocyclic ß-enamino esters with 1,2,3-triazole core, an enamino double bond between an ester group and an adjacent amino . Because of their extensive aromaticity the activity of amino group on these molecules are sharply decreased. We attempt to obtain some new •To receive any correspondence Vol. 6, No. 5, 2000 Synthesis and antibacterial activity of some hetercyclic ß-enamino esthers with 1,2,3-triazole 1.2.3-triazole derivatives (iminophosphoranes) with better reactivity through the reaction of the heterocyclic ß-enamino ester with triphenylphosphine. These iminophosphoranes which are becoming more and more important in organic synthesis, can react with carbonyl compounds to form Schiff base, carbon dioxide to give isothiocyanates and carbon disulfide to give isothiocyanates. They can also react with acids, alkylhalids, isocyanates, isothiocyanates and ozone. They can be used in Dials-Alder reaction and in the synthesis of heterocyclic compounds( 1). Therefore, we designed and sythesized some new heterocyclic ß-enamino ester derivatves— iminophosphoranes and tested their antibacterial activity. In this paper, we report the preparation of 1-substituted aryl-4-ethoxycarbonyl-5-amino-l, 2, 3triazole (compounds 4), 1-substituted aryl-4-ethoxycarbonyl-5-[(triphenylphosphoranylidene) amino]-l,2,3-triazole(iminophosphorane) (compounds 5), and the results on their antibacterial activity. Compounds 4c-4f and compounds 5. have not report in the literature. The products were characterized by IR, HNMR, MS and also through elemental analysis. The heterocyclic ß-enamino esters 4a-4i were prepared from 1-substituted aniline by diazotization reaction, treated with sodium azide, and then [2+3]cylization with moderate to good yields. Subsequently, heterocyclic ß-enamino esters were converted into the correspounding iminophosphorane dervatives ia-5i by treatment with triphenyphosphorane, hexachloroethane and triethylamine system (the Wamhoff methed(8)) in good yields(Scheme 1). The antibacterial activity of a solution of compounds 4-5 in acetone(0.01%) was measured using Scheme 1: For X=4f, p-OC2H5; 4g, m-Br; 5f, p-OCH,; 5g, m-Br; 5h, p-COCH3; 5i, m-F. 5b, m-N02; 5c, p-N02; 5d, p-CH3; 5e, p-Cl;

Synthesis of sterically encumbered 2,9-diaryl substituted phenanthrolines. key building blocks for the preparation of mixed (bis-heteroleptic) phenanthroline copper(i) complexes

Abstract: The preparation of several novel 2,9-diaryl phenanthrolines is described. Depending on the steric shielding the formation of bis-homoleptic phenanthroline copper(I) complexes can be suppressed and mixed phenanthroline complexes can be prepared. INTRODUCTION Metal phenanthroline complexes currently enjoy a renaissance because they find frequent use in exciting molecular structures (2), such as molecular knots (3), rotaxanes (4), dendrimers (5) and catenanes (6), as well as in enantioselective and supramolecular catalysts (7). Unfortunately, bisand trisphenanthroline complexes have mostly been limited to the general structure [M(L')n] (e.g. for Cu(I), Fe(II), Fe(III)) because of rapid ligand exchange processes. Only for Ru(II,III) the combination of different phenanthroline ligands L in mixed (heteroleptic) complexes [RuL'2L] and [RUL'LL] is known since their kinetic exchange is very slow (8). Obviously, many more combinations were possible if we had a strategy at hand to build mixed phenanthroline complexes of metal ions that are prone to rapid ligand exchange, such as copper(I) (9). We have recently shown (10) that the use of sterically encumbered groups in the 2and 9-position of phenanthrolines, such as in Δ (scheme 1), prevents formation of complexes of type [Cu(A2)]· In contrast, when phenanthroline A is reacted in presence of Cu(I) with a sterically unimpeded phenanthroline Β (e.g. without any 2,9substituents) mixed complexes'[Cu(A)(E)] are afforded in good yield (10). We now want to describe the synthesis of several novel phenanthroline ligands with bulky groups in positions 2 and 9, the steric shielding of which is appropriately tuned to use them for the formation of bis-heteroleptic phenanthroline copper(I) complexes. Of the following 2,9-diaryl phenanthrolines only 2f and l g have been described before (11).