Synthesis and structures of pyrimidinophanes containing a nitrogen atom in the bridge

The reactions of 1,3-bis(5-bromopentyl)-5-methyl-or 1,3-bis(5-bromopentyl)-6-methyl-uracil with benzylamine afforded pyrimidinophanes containing the nitrogen atom in the polymethylene bridge. Single-crystal X-ray diffraction study and NMR and UV spectroscopic study in solution demonstrated that the phenyl and uracil fragments in the macrocycles are in spatial proximity. Unlike the known macrocycles containing the pyrimidine ring, the pyrimidinophanes under study are conformationally rigid. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 539–547, March, 2006.     

Synthesis and antibacterial evaluation of nitrogen containing novel heterocyclic chalcones

Thirteen different novel heterocyclic chalcones were synthesized using cycloaddition and Claisen–Schmidt condensation reactions. These newly synthesized compounds were characterized by their spectral studies and structure of (E)-3-(4-methoxyphenyl)-1-(5-methyl-1-(pyridin-3-yl)-1H-1,2,3-triazol-4-yl)prop-2-en-1-one (4h) was also evidenced by single crystal X-ray studies. These compounds were evaluated for antibacterial activities against seven bacterial strains in vitro. Compounds 4b and 4c containing 4-fluoro and 4-chloro groups have shown remarkable inhibition as showed by the standard drug ciprofloxacin against Escherichia coli and Staphylococcus aureus, respectively. Another compound 4k containing 3,4,5-trimethoxy group also showed similar activity against both these strains. Beside these three potential compounds 4b, 4c, 4k, one more compound 4g containing 4-methyl group showed equivalent inhibition as that of standard drug against E. coli. These categories of compounds are therefore good candidates for developing new effective antibacterial in future.     

Synthesis of novel, potentially biologically active dibenzosuberone derivatives

Novel representatives of the important group of biologically active dibenzosuberone derivatives were prepared: 3,7-dibromo-5-(dimethylaminoethyl- oxyimino)-10,11-dihydro-5H-dibenzo[a,d]cyclohepta-1,4-diene (1), 3,7-dibromo-5-(3- dimethylaminopropylidene)-10,11-dihydro-5H-dibenzo[a,d]cycloheptene (2) and 1,7- dibromo-5-(3-dimethylaminopropylidene)-10,11-dihydro-5H-dibenzo-[a,d]-cycloheptene (3). These compounds are potential tricyclic antidepressants (TCAs), which are still the most frequently prescribed antidepressants in many countries.     

Syntheses and transformations of novel nitrogen and sulfur containing morphinanedienes

Summary The synthesis of 6-azido-6-demethoxythebaine (10) has been performed starting from thebaine (1). Compound10 undergoes a cycloaddition reaction with the azadienophilePTAD to form bridgehead azide14. The acid catalyzed rearrangement of isothiocyanato diene11 obtained from azido diene10 and thiocyanato dienes8 and9 leads to sulfur containing derivatives of apocodeine (17–20).

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Darstellung und Reaktionen stickstoff- und schwefelhaltiger Morphinandiene

Zusammenfassung 6-Azido-6-demethoxythebain (10) wurde ausgehend von Thebain (1) hergestellt. Verbindung10 wurde in einer Cycloadditionsreaktion mit dem AzadienophilPTAD zum Brückenkopfazid14 umgesetzt. Das aus dem Azidodien10 erhältliche Isothiocyanatodien11 und die bereits früher gewonnenen Thiocyanatodiene8 und9 liefern bei säurekatalysierter Umlagerung die Apokodeinderivate17–20.

     

Synthesis and study of novel fulleropyrrolidines bearing biologically active 1,4-dihydropyridines

New fulleropyrrolidines endowed with chlorine-containing biological active 1,4-dihydropyridines (1,4-DHPs) have been synthesised from the respective formyl substituted 1,4-DHPs by following Prato's procedure. The presence of the chlorine atom on C2 of the 1,4-DHP ring brings about important spectroscopical and structural differences in compounds 10a-f related to the parent hydrogen-containing 11a. The mass spectroscopy study reveals different fragmentation patterns for fulleropyrrolidines 10a-f and their precursors 1,4-DHPs, as well as with 11a. Semiempirical calculations (AM1 and PM3) predict a most stable stereoisomer in all cases (RS for 10a-f) and the same RR for 11a. The presence of chlorine atom in 10a-f is responsible for the higher calculated conformational energy barriers in comparison with 11a. The geometry of the 1,4-DHP shows that the presence of fullerene unit does not significantly alter the required conformation for biological activity.     

Synthesis of novel acyclonucleosides containing pyridazine

This paper presents the synthesis of some novel acyclonucleosides involving pyrrolo[2,3‐c]pyridazine and 4‐hydroxybutyl side chain.     

Synthesis of novel highly functionalized biologically active polycyclic caged amides

The synthesis of novel polycyclic amides has been achieved through the reaction of bishalomethyl pentacyclo[5.4.0.0^2,6.0^3,10.0^5,9]undecane diones with acyclic and cyclic secondary amines in the presence of an ionic liquid. Three of the compounds prepared have been found to possess antituberculosis activity.     

Synthesis and novel structure-activity relationships of potent sansalvamide A derivatives

Synthesis of twelve Sansalvamide A derivatives and their SAR against colon cancer (HT-29).     

Synthesis of novel texaphyrins containing lanthanides and boron

Texaphyrin macrocycles that contain gadolinium or lutetium, such as motexafin gadolinium and motexafin lutetium, are versatile anticancer therapeutics and diagnostics. Gadolinium texaphyrins substituted with carborane clusters could also find application in combined gadolinium and boron neutron capture therapy (GdB-NCT). The synthesis and characterization of novel texaphyrins containing gadolinium or lutetium in the pentaaza core and two carborane clusters bound to opposite pyrrol units of the macrocycle are described.     

Synthesis of nitrogen containing heterocycles over copper chromite

The reactions of 1,2-diaminopropane, 1-amino-2-propanol, 1-amino-2-ethanol and N-(-aminoethyl)-1,2-diaminoethane in the gas phase over copper chromite have been investigated with the objective of synthesising nitrogen containing heterocycles. At 240–360°C 1,2-diaminopropane gave principally methyl- and 2,5-dimethylpyrazine, whereas the basic reaction for 1-amino-2-propanol was dehydration to give 1-aminoethyl-2-methylaziridine (with a selectivity of up to 78%). The main cyclic product from the dehydration of 1-amino-2-ethanol was pyrazine, while piperazine was farmed together with pyrazine from N-(-amonoethyl)-1-2-diaminoethane.Latvian Institute of Organic Synthesis, Riga, LV-1006. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 950–957, July, 1994.     

Synthesis and characterization of diiron dithiolate complexes containing a quinoxaline bridge

A potential model complex for the hydrogenase active site, [Fe(2){(μ-CH(2)S)(2)R}(CO)(6)] (1) (R = quinoxaline), was synthesized by condensation of [(μ-LiS)(2)Fe(2)(CO)(6)] with 2,3-bis(bromomethyl)quinoxaline. Reactions of 1 with bis(diphenylphosphino)methane (dppm) under a range of conditions yielded substituted complexes [Fe(2){(μ-CH(2)S)(2)R}(CO)(5)(dppm)] (2), [Fe(2){(μ-CH(2)S)(2)R}(CO)(4)(k(2)-dppm)] (3) and [Fe(2){(μ-CH(2)S)(2)R}(CO)(4)(μ-dppm)] (4). X-ray crystallography confirms that in 2, the dppm is terminally bonded to an iron atom via one phosphorus atom, whereas in 3, it acts as a chelating ligand to coordinate to an iron center in a dibasal-substituted manner. In 4, the dppm bridges the two iron atoms in a cis basal/basal fashion with one phosphorus bonded to each iron atom. Treatment of 1 with various tertiary phosphines at room temperature in acetonitrile (MeCN) generates a range of mono-substituted products [Fe(2){(μ-CH(2)S)(2)R}(CO)(5)L] (5, L = PEt(3); 6, PMe(3); 7, PPh(3); 8, Me(2)PPh). With Bu(t)NC, mono- and di-substituted [Fe(2){(μ-CH(2)S)(2)R}(CO)(5)(Bu(t)NC)] (9) and [Fe(2){(μ-CH(2)S)(2)R}(CO)(4)(Bu(t)NC)(2)] (10) complexes are generated. All the complexes were characterized by elemental analysis, IR, MS and NMR spectroscopy. IR and NMR spectroscopic studies suggest that addition of excess HBF(4)·OEt(2) acid to 1-4 led to the protonation of quinoxaline nitrogen atoms. In contrast, 5-10 were not stable in acidic media. Electrochemistry of 1-4 was investigated in the acetonitrile medium (0.1 M Bu(4)NPF(6)). The electrochemical instability of the reduced ligand, quinoxaline, and the reduced forms of these complexes revealed from the electrochemical studies suggests that they do not provide ideal models of the hydrogenase active site.     

Synthesis of novel sulfur containing spirocyclic phosphoranes

The synthesis of new spirocyclic phosphoranes containing both sulfur and oxygen hetero atoms bonded to phosphorus is described.     

Synthesis of novel dendrimers containing pyrimidine units

A novel convergent approach to dendritic macromolecules is described in which 4,6-dichloro-2-(4-methoxyphenyl)-pyrimidine is used as the building block. The nucleophilic aromatic substitution reaction at this AB₂-monomer was used as the key step in the propagation of the dendrons. Different core reagents were used to form the dendrimers, including a 5,15-bis(pyrimidyl)porphyrin core. Fourth-generation dendrons and third-generation dendrimers could be synthesized. The presented dendrimers are promising candidates to be used in applications where a more rigid structure and a larger resistance towards the applied conditions is required.     

Synthesis, characterization, and biological study of some biologically potent schiff base transition metal complexes

The synthesis and characterization of a Schiff base derived from aniline and salicylaldehyde and its Co(II), Mn(II), and Zn(II) complexes is reported; several physical tools, in particular, elemental analysis, infrared and NMR techniques were used to investigate the chemical structure of the reported complexes. The ligand is found to be bound to the metal atom through the oxygen atom of the hydroxyl group, which is also supported by spectroscopic techniques. The results obtained by FT-IR and NMR showed that the Schiff base-transition metal complexes have octa hedral geometry. Biological screening of the complexes reveals that the Schiff base-transition metal complexes show significant activity against all microorganisms. The text was submitted by the authors in English.     

Synthesis of arylenealkyne conjugated macrocycles containing a long alkylene bridge

The synthesis of the first two arylenealkyne conjugated macrocycles containing a long alkylene bridge via Glaser coupling of template-directed tetraacetylenes was reported. Tetraacetylene intermediates with complex structures were constructed rapidly via quadruple Hagihara coupling of monoprotected bisacetylenes to appropriate tetraiodides and subsequent desilylation. The characterization of such compounds was carried out by NMR, GPC and UV-Vis spectra. Unfortunately, the two compounds were not liquid crystals and had no biaxial nematic mesophase character as expected. __________ Translated from Chemical Journal of Chinese Universities, 2007, 28(1): 65–70 [译自: 高等学校化学学报]     

Synthesis and biological evaluation of novel steroid-linked nitrogen mustards

Two novel steroid-linked nitrogen mustard conjugates 1a and 1b were synthesized by using estrogenic acid 4 coupled with aniline mustard 8 and phenol mustard 13 in an esterification or amidation procedure. Preliminary cytotoxic screening on cancer cell lines in vitro showed that, the steroid-ester linked nitrogen mustard conjugate la exhibited obvious increasing of activities.     

Synthesis of novel xanthone and acridone carboxamides with potent antiproliferative activities

Several new amino-substituted acridone and xanthone derivatives have been designed and synthesized, using an efficient methodology from suitable acridone- or xanthone-carboxylic acid intermediates. The antiproliferative activity of the target compounds has been evaluated against four cancer cell lines, namely breast adenocarcinoma MCF-7, acute lymphocytic leukemia CCRF-CEM, and its doxorubicin-resistant variant CEM/ADR5000 and prostate cancer PC-3 cell lines. Selected derivatives have also been tested against the urinary bladder T24 and metastatic melanoma WM266-4 cancer cell lines. Two nitro substituted acridones, bearing a basic side chain as well, were endowed with a remarkable profile against the majority of the cell lines tested, with IC₅₀ values in the low micromolar range. Both compounds cause accumulation at G0/G1 phase, induce apoptosis, and act as potent autophagy inhibitors in PC-3 cells, suggesting their further evaluation in various pathophysiological environments, conditions, and regimens.     

Synthesis and structure of novel 1,2-dihydro-phthalazine containing betaines

1,2-Dihydro-2-(4,5-dihydroimidazol-2yl)phthalazin-1-ol 1 reacts exothermically with dialkyl acetylenedicarboxylates to give 3-[2-(4,5-dihydro-1H-imidazol-3-iurn-2-yl)-1,2-dihydro-1-phthalazin]-1,4-dialkoxy-1,4-dioxo-2-buten-2-olates 7 and 8 . Enolic ester compounds underwent further transesterification reactions with formation of the betaines 9 and 10 . The unequivocal structural assignement of these compounds was achieved by spectroscopic ¹H and ¹³C nmr methods as well as X-ray analysis of 7 .     

Synthesis of pyrimidinophanes containing nitrogen atoms in polymethylene bridges

The reactions of 1,3-bis(-bromobutyl- or -pentyl)-6-methyluracil with 1,3-bis(-ethylaminobutyl- or -pentyl)-6-methyluracil afforded pyrimidinophanes containing N atoms in bridging polymethylene chains. Individual geometric isomers of pyrimidinophanes were isolated. The structure of one of these isomers was established by X-ray diffraction analysis. Quaternization of the bridging N atoms with o-nitrobenzyl bromide gave rise to water-soluble pyrimidinophanes.     

含全氟烷基磺酰基新型异黄酮化合物的合成

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