Antal Csampai

• DSC
• Professor (Full) at Eötvös Loránd University

Our ongoing research focuses on the development of new imipridone derivatives. We aim to design compounds that can completely and selectively eradicate cancer cells after relatively short treatment. We have synthetized systematically designed novel hybrids and evaluated their antiproliferative activity against PANC-1 and Fadu cell lines. We have al...

Our ongoing research focuses on developing imipridone derivatives capable of complete and selective eradication of cancer cells after relatively short treatment. We have synthetized systematically designed novel hybrids and evaluated their antiproliferative activity on PANC-1 and Fadu cell lines. We have also conducted preliminary studies on the me...

Citation: Ferenczi, E.; Keglevich, P.; Tayeb, B.A.; Minorics, R.; Papp, D.; Schlosser, G.; Zupkó, I.; Hazai, L.; Csámpai, A. Synthesis and Antiproliferative Effect of New Alkyne-Tethered Vindoline Hybrids Containing Pharmacophoric Fragments. Int. J. Mol. Sci. 2024, 25, 7428. https://doi. Abstract: In the frame of our diversity-oriented research on...

In the frame of our diversity-oriented research on multitarget small molecule anticancer agents, utilizing convergent synthetic sequences terminated by Sonogashira coupling reactions, a preliminary selection of representative alkyne-tethered vindoline hybrids was synthesized. The novel hybrids with additional pharmacophoric fragments of well-docume...

A library of regioisomeric monoterpene-based aminodiols was synthesised and applied as chiral catalysts in the addition of diethylzinc to benzaldehyde. The synthesis of the first type of aminodiols was achieved starting from (−)-8,9-dihydroperillaldehyde via reductive amination, followed by Boc protection and dihydroxylation with the OsO4/NMO syste...

Pseudoproline derivatives such as Thr(ΨPro)-OH are commonly used in peptide synthesis to reduce the likelihood of peptide aggregation and to prevent aspartimide (Asi) formation during the synthesis process. In this study, we investigate notable by-products such as aspartimide formation and an imine derivative of the Thr(ΨPro) moiety observed in flo...

A series of novel triazole-tethered ferrocenoylamino-substituted cinchona–chalcone hybrids along with two representative benzoylamino-substituted reference compounds were prepared by three methods of CuAAC chemistry. In line with the limited success or complete failure of attempted conversions with low catalyst loadings, by means of DFT modeling st...

The synthesis of d-glucosamine-1-carboxylic acid based β-sugar amino acids (β-SAAs) is typically performed in nine consecutive steps via an inefficient OAc → Br → CN conversion protocol with low overall yield. Here, we present the improved and more efficient synthesis of both Fmoc-GlcAPC-OH and Fmoc-GlcAPC(Ac)-OH, β-SAAs consisting of only 4–5 synt...

The synthesis of D-glucosamine-1-carboxylic acid based β-sugar amino acids (β-SAAs) is typically performed in nine consecutive steps via an inefficient OAc→Br→CN conversion protocol with low overall yield. Here we present the improved and more efficient synthesis of both Fmoc-GlcAPC-OH and Fmoc-GlcAPC(Ac)-OH, β-SAAs consisting of only 4-5 synthetic...

In a search for novel therapeutic options for head and neck squamous cell carcinomas (HNSCCs) generally treated with limited therapeutic success, we synthesized a series of novel erlotinib–chalcone molecular hybrids with 1,2,3-triazole and alkyne linkers and evaluated them for their anticancer activity on Fadu, Detroit 562 and SCC-25 HNSCC cell lin...

6-Hydroxyquinoline and 3-hydroxyisoquinoline as N-containing naphthol analogues were tested in modified Mannich reactions (mMr’s). In the case of 6-hydroxyquinoline, the outcomes of the attempted Mannich reactions were strongly influenced by the amine components. Aminoalkylation of this substrate with reagents 1-naphthaldehyde and N-benzylmethylami...

Utilizing McMurry reactions of 4,4'-dihydroxybenzophenone with appropriate carbonyl compounds, a series of 4-Hydroxytamoxifen analogues were synthesized. Their cytotoxic activity was evaluated in vitro on four human malignant cell lines (MCF-7, MDA-MB 231, A2058, HT-29). It was found that some of these novel Tamoxifen analogues show marked cytotoxi...

Fibronectin is an extracellular matrix component that plays a significant role in many physiological processes, such as cell adhesion, growth, differentiation, and migration. In this study, we revealed the interaction between this important protein and the widely studied natural active substance green tea polyphenol epigallocatechin-gallate (EGCG)...

This paper presented the efficiency of different Pd-based catalytic systems in a series of SM reactions of 4,5-dibromo-2-methylpyridazin-3(2H)-one with ferroceneboronic acid, ferrocene-1,1′-diboronoc acid, and its bis-pinacol ester. In addition to the disubstituted product, these transformations afford substantial amounts of isomeric 4- and 5-ferro...

Imipridones, including ONC201, ONC206 and ONC212 (which are emblematic members of this class of compounds developed by Oncoceutics) constitute a novel class of anticancer agents, with promising results in clinical trials. With the aim of increasing the ROS (reactive oxygen species) responsivity of the synthesized molecules, a set of novel ferrocene...

A new library of pinane-based 1,4-amino alcohols was synthesised and utilised as chiral ligands in enantioselective diethylzinc addition to benzaldehyde. Aldol condensation of (+)-nopinone, derived from (–)-β-pinene, with 2-pyridinecarboxaldehyde gave the key intermediate α,β-unsaturated ketone, which was transformed in diastereoselective reduction...

Tamoxifen is a long-known anti-tumor drug, which is the gold standard therapy in estrogen receptor (ER) positive breast cancer patients. According to previous studies, the conjugation of the original tamoxifen molecule with different functional groups can significantly improve its antitumor effect. The purpose of this research was to uncover the mo...

Chemotherapy is an indispensable tool to treat cancer, therefore, the development of new drugs that can treat cancer with minimal side effects and lead to more favorable prognoses is of crucial importance. A series of eleven novel 1,2,4-thiadiazoles bearing erlotinib (a known anticancer agent), phenylethynyl, ferrocenyl, and/or ferrocenethynyl moie...

Combination antitumor treatments are essential parts of modern tumor therapy as—compared to monotherapies—(i) they are more effective; (ii) the dose of the compounds can be reduced; and (iii) therefore the side effects are improved. Our research group previously demonstrated the antitumor character of bortezomib (BOZ) in A2058 melanoma cells. Unfor...

By means of the annulation of easy-to-handle yet sufficiently reactive (Sp)-2-formylferrocenecar- bonyl fluoride with the hydrochlorides of cysteamine and the methyl esters of enentiomer cysteines conducted in dichloromethane at room temperature in the presence of pyridine, the first members of 2,3-dihydroferroceno[3,4]pyrrolo[2,1-b]thiazol-5(8bH)-...

The syntheses of hydroxy-substituted kynurenic acid (KYNA) derivatives have been achieved by an optimised Conrad–Limpach procedure. The derivatives were then reacted with morpholine and paraformaldehyde, as a representative amine and aldehyde, in a modified Mannich reaction. The newly introduced substituents altered the preferred reaction centre of...

Hybrid compounds combine fragments with complementary targets to achieve a common pharmacological goal. This approach represents an increasingly popular strategy for drug discovery. In this work, we aimed to design antitumor hybrid compounds based on an inhibitor of ataxia-telangiectasia and Rad3-related protein (ATR)-dependent signaling, protoapig...

Use of a Pictet-Spengler reaction of tryptamine and l-tryptophan methyl ester and subsequent reduction of the nitro group followed by further cyclocondensation with aryl aldehydes and formyl–substituted carboxylic acids, including ferrocene-based components, furnished a series of diastereomeric 6-aryl-substituted 5,6,8,9,14,14b-hexahydroindolo[2',3...

Aryl 2,2,2-trifluoroethyl sulfides were synthesized by copper(I)-catalyzed nucleophilic aromatic substitution reaction (Goldberg- Ullmann coupling).The method requires aryl iodides and 2,2,2-trifluoroethylthioacetate as starting materials, benzyl amine as solvent and base, and copper(I) bromide as a catalyst.The reaction mixture was stirred at 110°...

The application of kynurenic acid (KYNA) as an electron-rich aromatic system in the modified Mannich reaction has been examined. The extension possibility of the reaction was tested by using amines occurring in a number of bioactive products, such as morpholine, piperidine, or N-methylpiperazine and aldehydes of markedly different reactivities, lik...

A novel, multifunctional group mediated one-step derivatization (MGOD) method has been developed employing the couples of hexamethyldisilazane (HMDS) and perfluorocarboxylic acid (PFCA). 1 MGOD relies on the unique reactivity of HMDS and PFCA to provide simultaneous trialkylsilylation and acylation in a single step. While primary aliphatic amines a...

By means of copper(I)-and ruthenium(II)-catalyzed click reactions of quinine- and quinidine-derived alkynes with azide-substituted chalcones a systematic series of novel cinchona-chalcone hybrid compounds, containing 1,4-disubstituted- and 1,5-disubstituted 1,2,3-triazole linkers, were synthesized and evaluated for their cytotoxic activity on four...

Several promising anti-cancer drug–GnRH (gonadotropin-releasing hormone) conjugates have been developed in the last two decades, although none of them have been approved for clinical use yet. Crizotinib is an effective multi-target kinase inhibitor, approved against anaplastic lymphoma kinase (ALK)- or ROS proto-oncogene 1 (ROS-1)-positive non-smal...

Inspired by the well-established clinical evidence about the interplay between apoptotic TRAIL (tumour necrosis factor-related apoptosis-inducing ligand) mechanism and reactive oxygen species (ROS)-mediated oxidative stress, a set of novel ONC201 hybrids containing the impiridone core and one or two differently positioned ferrocenylalkyl groups wer...

A library of monoterpene-based aminodiols was synthesized and applied as chiral catalysts in the addition of diethylzinc to benzaldehyde. The reduction of a bicyclic α-methylene ketone, derived from natural (-)-limonene followed by epoxidation, gave the key epoxy alcohol intermediate. Ring opening of the oxirane ring with primary amines induced by...

Nanoparticles consist of biodegradable poly(D,L-lactic-co-glycolic acid) (PLGA) are promising carriers for drug molecules to improve the treatment of tuberculosis. Surface modifiers, such as Pluronic F127, are essential for biocompatibility and for the protection against particle aggregation. This study demonstrates a successful approach to conjuga...

Synthesis, structure determination, and in vitro antiproliferative effect of 4,5-dihydronaphto[1,2-d][1,2,3]selenadiazole (1) and 4,5-dihydrobenzoferroceno[1,2-d][1,2,3]selenadiazole (2) are presented. The synthesized molecules were characterized by NMR, IR, Raman, mass, and UV spectroscopies. The equilibrium structures of 1 and 2 were calculated u...

The reaction of aryl iodides, 3-mercaptopropionic acid, and Cu2O in refluxing pyridine resulted in the formation of 3-(arylthio)propionic acids in good to excellent yield. The latter 3-(arylthio)propionic acids — as novel aryl mercaptan equivalents — gave aryl mercaptans or diaryl disulfides, respectively, on reductive (Na2S) or oxidative (I2) clea...

Employing an optimized Pd-catalyzed cross-coupling reaction promoted by CuI, novel N-ferrocenylpyridazinones along with N-phenyl- and N-(2-pyridyl) analogues were synthesized from readily available heterocyclic precursors, iodoferrocene, iodobenzene and 2-bromopyridine. With exception of the ferrocenylation of 6-ferrocenylpyridazin-3(2H)-one yieldi...

Recently, we demonstrated that ferrocene- containing compounds with cinchona moiety displayed marked anticancer activity. Here we report on the effects of most promising isomers encompassing quinine- (compounds 4 and 5) and quinidine- epimers (compounds 6 and 7) - synthesized by improved methods providing controlled diastereoselectivity - in three...

New naphth[1,3]oxazino-benzazepines and -thienopyridines were synthesized using a modified Mannich-type synthetic pathway by the reaction of 4,5-dihydro-3H-benz[c]azepine or 6,7-dihydrothieno[3,2-c]pyridine and different substituted aminonaphthols. Reaction conditions were optimized using microwave irradiation, with relatively short reaction times...

The Staudinger ketene-imine cycloaddition reactions of cyclobrassinin phytoalexin analogues 2-aryl-4,9-dihydro-1,3-thiazino[6,5-b]indoles with chloroacetyl chloride as a ketene source were investigated under different conditions. Both β-lactam ring formation and the N-chloroacetylation of the indole moiety took place. The indole N-chloroacetyl grou...

The interaction of the anti-adhesive coating, poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) and its Arg-Gly-Asp (RGD) functionalized form, PLL-g-PEG-RGD, with the green tea polyphenol, epigallocatechin-gallate (EGCg) was in situ monitored. After, the kinetics of cellular adhesion on the EGCg exposed coatings were recorded in real-time. The...

2-Ferrocenyl-4H-benzo[e][1,3]thiazine and its 6,7-dimethoxy derivative were prepared by a Bischler–Napieralski-type annulation of the Mannich adducts of ferrocenecarboxamide, formaldehyde, and the corresponding thiophenol. A more efficient synthetic pathway, comprising a directed lithiation/iodination sequence followed by standard functional-group...

A novel, structure-related derivatization principle has been developed in order to quantify cathinone-type synthetic drugs (CTSDs), focusing on the most common pentedrone (PENT), including also 4-fluoromethcathinone (4-FMC), methcathinone (MCTN), 4-methylethcathinone (4-MEC), 3,4-dimethylmethcathinone (3,4-DMMC), and 4-ethylmethcathinone (4-EMC). F...

A library of title ligands (12 examples) is prepared starting from (S)-(-)-perillaldehyde and tested in the reaction of aldehydes (III) with ZnEt2.

The "classical" challenge, raised by Emil Fischer as to why one monosaccharide arylhydrazone adopts a cyclic structure but another an acyclic structure, is answered here. The present comprehensive analysis of hexose and hexosamine arylhydrazones, based on 2D NMR spectroscopy and theoretical modeling, has established that the chain of hydrogen bonds...

Combined computational-experimental studies were carried out to parallel two mechanistic models for tetrahydropyranylation of alcohols catalyzed by Schreiner’s thiourea. The results challenge the common mechanistic view that the catalytic effect is related to stabilizing double hydrogen-bonding interactions between the thiourea and the alcohol, whi...

A library of tridentate aminodiols, derived from naturally occurring (R)-(+)-pulegone, was synthesized and applied as chiral catalysts in the addition of diethylzinc to benzaldehyde. The reduction of pulegone furnished pulegol, which was transformed into allylic trichloroacetamide via Overman rearrangement of the corresponding trichloroacetimidate....

The reductive amination of (-)-2-carene-3-aldehyde, prepared in two steps from (-)-perillaldehyde, furnished 2-carene-based allylamines. tert-Butyloxycarbonyl (Boc) or carbobenzyloxy (Cbz) protection of the resulting amines, followed by stereoselective dihydroxylation in highly stereospecific reactions with OsO4 and subsequent deprotection, resulte...

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and...

The selective deprotection of Nω-nitro-arginine derivatives represents a major preparative challenge. This problem can be circumvented by the use of catalytic hydrogenation, but often high pressure, elevated temperature, and/or long reaction times are needed. In certain cases hydrogenation is not suitable, for example, small-scale reactions, parall...

The mechanism of the addition of acetylacetone to β-nitrostyrene catalyzed by a cinchona based squaramide catalyst was studied in detail under synthetically relevant conditions. The reaction was monitored by in situ IR and 1H-NMR spectroscopy and a reaction mechanism was proposed based on these kinetics experiments. It was found that the reaction s...

Prior to any chromatographic analysis of N-(phosphonomethyl)glycine, glyphosate (GLYP) and its principal metabolite aminomethylphosphonic acid (AMPA) - being particularly polar herbicides - first, derivatization needs to be the performed.In this paper, for GLYP and AMPA for the time being not applied, alkylsilyl derivatization speciation is describ...

An organocatalytic iterative assembly line has been developed in which nitromethane was sequentially coupled with two different enones using the combination of pseudo-enantiomeric cinchona based thiourea catalysts. Application of unsaturated aldehydes and ketones in the second step of the iterative sequence allows the constructions of cyclic syn-ke...

Quantification, stability and unique spectroscopic properties of indolinyl-caged glutamates (ICGs), with the o-phthalaldehyde-3-mercaptopropionic acid (OPA-MPA) reagent, were described, at first. As new principle to the field, reactivity and stoichiometry of variously substituted OPA-MPA derivatized ICGs, such as 4-methoxy-7-nitroindolinyl-(MNI-Glu...

We report a comparative analysis of plasmin detection by means of electrochemical biosensor and photometric assays. The biosensor has been based on ferrocene-modified peptide (Fc-P) specific to plasmin. Fc-P substrate is enzymatically cleaved by plasmin and the short fragment of peptide contained Fc is released causing decrease of redox current mea...

A novel, selective acylation of primary phenylalkyl amines (PPAAs) using hexamethyldisilazane (HMDS) & perfluorocarboxylic acids (PFCAs) is noted. Couples, like HMDS & trifluoroacetic acid (TFA), or HMDS & pentafluoropropionic acid (PFPA), or HMDS & heptafluorobutyric acid (HFBA) trigger PPAAs' quantitative acylation. Processes' selectivity was cha...

In literature a considerable attention has been paid to different classes of cross-coupling chemistry of ferrocene-based precursors to obtain a variety of target compounds relevant in material science, catalysis and biological tests. The majority of these reactions are Suzuki- or Sonogashira-coup¬lings, but there are only scattered examples for Buc...

The heterogeneous asymmetric direct aldol reactions between aldehydes (2-nitrobenzaldehyde, 2-methylpropanal) and ketones (acetone, cyclohexanone) in the presence of polystyrene (PS) resin supported di- and tripeptides were studied under otherwise identical experimental conditions at room temperature in batch reactor. For all three asymmetric aldol...

Starting from (Sp)-ferroceno[d]pyridazin-1(2H)-one a series of novel ferrocene-fused heterocycles with planar- and central chirality were synthesised. The thione analogue of the precursor obtained by treatment with Lawesson reagent underwent facile mercury-mediated aminations with a selection of aminoalcohols. The resulted intermediates were subjec...

Recent advances and applications in anticancer treatment, mainly chemotherapy, have reported highly active organometallic, mainly heterocyclic ferrocene compounds. Several in vitro and in vivo tests of molecules containing ferrocene combined with chalcone or triazole or cinchona alkaloid motifs have proven their anticancer and antimicrobial effect...

Synthesis, structure determination and in vitro antiproliferative assay of a series of novel ferrocenenyl hydrazones containing 4-halopyridazin-3(2H)-one fragment(s) and three representative N-aryl-substituted (Sp)-ferroceno[d]pyridazinones are presented. The model compounds can be considered as different assemblies of the potential binding sites c...

An efficient microwave-assisted Pictet–Spengler protocol employing boric acid/acetic acid as a catalytic system was elaborated for the synthesis of 1-aryl-β-carbolines. Under the novel conditions tryptamine and 2-formylbenzoic acid furnished a pentacyclic skeleton in a single step, whereas using o-phthalaldehyde as a coupling partner led to the for...

Dinuclear rhodium complexes have attracted considerable attention as a result of their chemical and biological reactivity. We report herein the synthesis and structural elucidation by combined spectroscopic methods of a new rhodium complex containing N-methyl-d-phenylalaninate (NMfO–) as a chiral ligand. It has been demonstrated that the structure...

A seri es of 2- arylmethylideneferroceno[ e ]cyclohexanon e was prepared by base-c atalysed conde nsation of ferroceno[ b ]cyclohexa none with a variety of aryl aldehyde s including for mylferrocen e. The decreased reactivity of these novel chal cones towards nucleop hic reagents was in terpreted by the compa rison of DFT reactivity in dices calcul...

Ketene–imine cycloaddition reactions between cis- and trans-2-aryl-4a,5,6,7,8,8a-hexahydro-4H-3,1-benzothazines and chloroacetyl chloride in the presence of base were investigated. Because of the diastereotopic CN faces of cyclohexane-condensed thiazines, both of the possible Staudinger addition product monochloro-β-lactam stereoisomers were obtain...

A series of novel functionalized mono-, bis- and tris-(S)-{[(2S,4R,8R)-8-ethyl-quinuclidin-2-yl](6-methoxyquinolin-4-yl)}methanamines including ferrocene-containing derivatives was obtained by the reaction of the precursor amine with a variety of acylation agents. Their in vitro antitumor activity was investigated against human leukemia (HL-60), hu...

The potential of a series of cinchona-based organocatalyst candidates was investigated by comparative DFT analysis of the crucial bond-forming step of the enantioselective Michael addition of nitromethane to 1,3-diphenylpropenone. It was shown that the applied methods are feasible to investigate the influence of functional groups on the activation...

The ring transformations of dichloro-β-lactam-fused 2-aryl-1,3-benzothiazines with sodium methoxide were investigated. With 2 equiv of base, the dichloro-β-lactam derivatives underwent rearrangement and dihydro-1,4-benzothiazepines, 3,4-substituted isoquinolines and substituted thiazole disulfides were isolated. A possible reaction mechanism is pro...

Chiral salen complexes with C2-symmetry were prepared by the complexation of a selection of transition metal salts with a novel ligand obtained via controlled diastereoselective diaza-Cope rearrangement of a diimine which was resulted from the condensation 2,2′-[(1R,2R)-1,2-diaminoethane-1,2-diyl]diphenol with formylferrocene. On the effect of air...

We report a convenient approach for the synthesis of a new ring system: 4,5-dihydro-1,3-thiazino[5,4-b]indoles. The procedure involves the use of Lawesson's reagent in the presence of silica to achieve the one-step ring-closure reactions of 2-benzoylamino-3-hydroxymethylindole intermediates to furnish 4,5-dihydro- 2-aryl-1,3-thiazino[5,4-b] indoles...

ortho-Nitrophenyl-substituted condensed 1,3-benzothiazines proved to be a useful core unit in indole syntheses under non-reductive conditions. Thus, the treatment of ortho-nitro-2-aryl-2a-chloro-4H-azeto[2,1-b][1,3]benzothiazin-1-ones with sodium methoxide in methanol provided indolo-1,4-benzothiazepines via a novel rearrangement. Through the sulfu...

Reactions of derivatives of the isoquinoline analog trans-2,2a-diaryl-2,2a- dihydro-5,6- dimethoxy-1H,8H-azeto[2,1-b][1,3]benzothiazin-1-one were studied under basic conditions. Their treatment with sodium methoxide in methanol resulted first in alcoholysis of the β-lactam ring, followed by opening of the thiazine ring and oxidation of the thiol mo...

Treatment of thia analogues of protoberberine alkaloids, 13-carboxy-13,13a-dihydro-6H,8H-isoquinolino [2,3-c][1,3]benzothiazin-8-ones, with thionyl chloride, followed by ethanol, unexpectedly provided 5,11-dioxoindeno [1,2-c]isoquinoline derivatives containing a novel ring system. Elucidation of their structures is presented in this paper. The anti...

N-methoxy-carbamate (II) converts oxo compounds to O-methyl oximes whereas N-methyl-carbamate (X) reacts to give the corresponding imines.

A method for the synthesis of medium-sized 1,5-benzothiazocines by ring enlargement of 1,3-benzothiazines has been developed. When N-alkyl-1,3-benzothiazines were reacted with dimethyl acetylenedicarboxylate in acetonitrile at room temperature, regioisomeric 5,6-dihydro-2H-1,5-benzothiazocines and 5,6-dihydro-4H-1,5-benzothiazocines were obtained a...

The ring-enlargement reactions of monochloro-β-lactam-fused 2-aryl-1,3-benzothiazines revealed that the reactions of ortho-nitro aryl-substituted derivatives with sodium methoxide in methanol provided two products, depending on the amount of the base. With 2equiv of reagent, the expected 1,4-benzothiazepines were obtained. Somewhat surprisingly, tr...

By means of a base-catalysed ring enlargement of triazapentalenoindenes resulting from diasteroselective anhydride-induced ring transformation of chiral aminoalcohol-derived zwitterionic 2,3-dihydroimidazo[2,1-a]phthalazinium-olates, a series of pyrazolo[1,5-d][1,4]diazocin-7(6H)-ones with central and conformational chirality were obtained in enant...

A series of planar chiral ferroceno[d]pyridazinones was prepared by hydrazine-mediated cyclisations of (Sp)-2-formylferrocenoyl fluoride obtained in two steps from (2S,4S)-4-(methoxymethyl)-2-ferrocenyl-1,3-dioxane. Further derivatives based on the novel heterocyclic scaffold were resulted by means of the facile N-alkylation reactions carried out o...

The reactions between different N,O-bis-trimethylsilyl-carbamates and oxo compounds were studied. The N,O-bis-trimethylsilyl-N-methoxy-carbamate converts ketones to the corresponding O-methyl oximes. The product is usually a mixture of syn and anti isomers. If the carbonyl compound bears a hydroxyl group, the oxime formation and the O-silylation ta...

The reactions of 5-chloro-6-phenyl-,4,5-dichloro-6-phenyl- and 5-chloro-6-(2,4-dichlorophenyl)-2-methylpyridazin-3(2H)-ones with 57% aqueous hydrogen iodide or sodium iodide in dimethyl formamide, respectively, are described. Upon treatment of chloro compounds with 57% hydrogen iodide, besides nucleophilic substitution of chloro- by iodo substituen...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A series of novel aryl-substituted β-lactams condensed with 1,3-benzothiazines, isoquinolines or 1,4-benzothiazepine were obtained by means of the Staudinger reaction and isomerized in the presence of sodium methoxide to the thermodynamically more stable form. The structures of the new molecules were determined by NMR spectroscopy. Theoretical calc...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

In boiling 48% HBr conversions of title compounds (-) resulted in 2-(ω)-bromoalkyl)-4-(2-hydroxyethylamino)-phthalazinones ,, angular tricycles ,- and the tricyclic dione, respectively, depending on the lengths of the side chains and the reaction time applied. The large difference between the reactivities of 4-(2-hydroxyethylamino)- and 4-(3-hydrox...

For Abstract see ChemInform Abstract in Full Text.

On simultaneous effect of iodine-catalysis and microwave irradiation Schiff bases deactivated by electron-donating C-phenothiazinyl- and ferrocenyl-substituents, respectively, underwent formal inverse electron demand aza-Diels-Alder (DA) cycloaddition with 3,4-dihydro-2H-pyrane (DHP) employed as donor component. Depending on the substitution patter...

A convenient synthesis was devised for rare 2,3-disubstituted 4,5-dihydro-1,4-benzothiazepines from 2-aryl-4H-1,3-benzothiazines. The Staudinger reaction of 1,3-benzothiazines obtained with chloroacetyl chloride selectively furnished trans-monochloro-beta-lactam-condensed thiazines. The ring expansion of azeto[2,1-b][1,3]benzothiazin-1-one derivati...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A series of novel ferrocene-containing-dihydropyrimidines (DHPs) were prepared by three-component Biginelli reactions of formylferrocene, 1,3-dioxo-components and thiourea catalyzed by boric acid and ytterbium triflate, respectively. When cyclic-1,3-diones were employed as dioxo component in the reactions promoted by boric acid, besides one expecte...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The dichloro-β-lactam ring, obtained via Staudinger reaction of 4-aryl-2H-1,3-benzothiazines, proved to be a useful protecting strategy for the synthesis of 4-aryl-2H-1,3-benzothiazine 1,1-dioxides. After oxidation of the 1,1-dichloroazeto[2,1-c][1,3]-benzothiazin-2-ones, the thiazine ring could be recovered selectively and in good yield by treatme...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The desmotropy of differently substituted (R∗)-3-ethoxycarbonyl-2-aryl-3,5-dihydro-4,1-benzothiazepines and 3-ethoxycarbonyl-2-aryl-1,5-dihydro-4,1-benzothiazepines was investigated. The target 4,1-benzothiazepines were obtained via the ring transformation of (2R∗,2aS∗)-2-chloro-2a-aryl-2,2a-dihydro-2H,4H-azeto[1,2-a][3,1]benzothiazin-1-ones with s...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.