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Hristea E.N.,Institute of Physical Chemistry Ilie Murgulescu | Bem M.,Institute of Physical Chemistry Ilie Murgulescu | Balaban T.S.,CNRS Institute of Molecular Sciences of Marseilles | Eichhofer A.,Karlsruhe Institute of Technology | And 11 more authors.
Arkivoc | Year: 2011

In a quest for novel persistent free radicals, two products were obtained from the reaction between 1,1-diphenylhydrazine and 4-chloro-7- nitrobenzofurazan: the expected 1-(4-nitrobenzofurazan-7-yl)-2,2-diphenyl- hydrazine 3 formed via an S NAr process, and the unexpected 4,7-benzofurazandione-(bis-1,1-diphenylhydrazone) 4 formed from 3 by a further ipso substitution and dehydrogenation. Oxidation of 3 with solid PbO 2 or solid KMnO 4 at room temperature affords during the first few minutes a persistent mono-nitro-hydrazyl free radical 6, which reacts with NO 2 and forms another persistent hydrazyl free radical 7 having two nitro groups. Two blue dimeric compounds, 11 and 13, were obtained by dimerisation of 6 and 7 respectively, and loss of N 2O 4, and their structures were determined by mass spectrometry and NMR spectra. Additionally, single crystal X-ray diffraction was used to ascertain the structures of compounds 4 and 13. Other novel derivatives were prepared either by N-alkylation of 3 with methyl iodide, which afforded compound 5, or by homolytic nitration of 3 with gaseous NO 2 which yielded the 4,7-dinitrobenzofurazan derivative 8. When gaseous 15NO 2 was used in a similar reaction, only one 15N-nitro group was present in the product 7. Persistent free radicals were obtained from 4, 11, or 13 with KMnO 4. Cyclic voltammograms for 3 and 8 as well as electronic absorption spectra for all new compounds 3, 4, 5, 8, 11, and 13 are discussed. © ARKAT-USA, Inc.


Oprea O.,Polytechnic University of Bucharest | Bem M.,Ilie Murgulescu Institute of Physical Chemistry | Caproiu M.T.,Romanian Academy of Sciences | Draghici C.,Romanian Academy of Sciences | And 8 more authors.
Revue Roumaine de Chimie | Year: 2013

2-Mercaptobenzothiazole (1) reacts with halo-nitro-aromatics (2a-2g) by nucleophilic substitution yielding crystalline sulfides (3a-3g). The following halo-nitro-aromatics were employed: 2a, 4-chloro-7-nitrobenzofurazan or NBD-Cl; 2b, picryl chloride; 2c, 1-fluoro-2,4-dinitrobenzene; 2d, 2-chloro- 3,5-dinitropyridine; 2e, 1,5-difluoro-2,4-dinitrobenzene; 2f, 4-chloro-3,5-dinitro-trifluorotoluene, and 2g, 2-chloro-3,5- dinitrotrifluorotoluene. Also 2-mercaptobenzoxazole (4) reacts with NBD-Cl (2a) yielding crystalline sulfide (5). Compounds 3a and 5, two benzofurazan derivatives, are fluorescent (3a, which has more intense fluorescence than 5, was investigated by X-ray crystallography, differential scanning and thermal calorimetry, electronic absorption and emission spectrometry in solution and in solid state). All compounds were characterized by MS, 1H-NMR, 13C-NMR, IR, electronic absorption spectrometry, and reversephase thin-layer chromatography which led to the determination of molecular hydrophobicities.


Tanase C.,Romanian National Institute for Chemical Pharmaceutical Research and Development | Caproiu M.T.,Romanian Academy Organic Chemistry Center nitescu | Draghici C.,Romanian Academy Organic Chemistry Center nitescu | Enache C.,Central Laboratory for Phytosanitary Quarantine | And 2 more authors.
Revista de Chimie | Year: 2011

Removing of the benzoate protecting groups of the O2, O 4- and N1,O4-bis alkylated 5-fluorouraal derivatives was performed by transesterification with K2CO 3 in methanol-tetrahydrofurane. From this deprotection some intermediates and secondary products were isolated and characterized. Their structure was assessed by MS, IR, 1H- and 13C-NMR (with complementary COSY and HETCOR spectra). A preliminary in vitro screening of their anti-neoplastic activity on U937 monocytic blasts showed that only the final deprotected O2, O4compound (4) was cytotoxic and that the presence of two bicycles in the O2,O4 positions is critical for its antineoplastic activity. Moreover we showed indirectly that intracellular phosphorylation of this nucleoside analog might underlie its mechanism of action.


Tnase C.I.,Romanian National Institute for Chemical Pharmaceutical Research and Development | Drghici C.,Organic Chemistry Center Cdnenitescu | Cojocaru A.,Romanian National Institute for Chemical Pharmaceutical Research and Development | Galochkina A.V.,Influenza Research Institute | And 5 more authors.
Bioorganic and Medicinal Chemistry | Year: 2015

New nucleoside analogues with an optically active bicyclo[2.2.1]heptane skeleton as sugar moiety and 6-substituted adenine were synthesized by alkylation of 6-chloropurine intermediate. Thymine and uracil analogs were synthesized by building the pyrimidine ring on amine 1. X-ray crystallography confirmed an exo-coupling of the thymine to the ring and an L configuration of the nucleoside analogue. The library of compounds was tested for their inhibitory activity against influenza virus A\-California/07/09 (H1N1)pdm09 and coxsackievirus B4 in cell culture. Compounds 13a and 13d are the most promising for their antiviral activity against influenza, and compound 3c against coxsackievirus B4. Compounds 3b and 3g were tested for anticancer activity. © 2015 Elsevier Ltd.


PubMed | Petru Poni Institute of Macromolecular Chemistry, Organic Chemistry Center Cdnenitescu, Influenza Research Institute, Romanian National Institute for Chemical Pharmaceutical Research and Development and Central Laboratory for Phytosanitary Quarantine
Type: Journal Article | Journal: Bioorganic & medicinal chemistry | Year: 2015

New nucleoside analogues with an optically active bicyclo[2.2.1]heptane skeleton as sugar moiety and 6-substituted adenine were synthesized by alkylation of 6-chloropurine intermediate. Thymine and uracil analogs were synthesized by building the pyrimidine ring on amine 1. X-ray crystallography confirmed an exo-coupling of the thymine to the ring and an L configuration of the nucleoside analogue. The library of compounds was tested for their inhibitory activity against influenza virus ACalifornia/07/09 (H1N1)pdm09 and coxsackievirus B4 in cell culture. Compounds 13a and 13d are the most promising for their antiviral activity against influenza, and compound 3c against coxsackievirus B4. Compounds 3b and 3g were tested for anticancer activity.


Tanase C.I.,Romanian National Institute for Chemical Pharmaceutical Research and Development | Draghici C.,Organic Chemistry Center Cdnenitescu | Caproiu M.T.,Organic Chemistry Center Cdnenitescu | Shova S.,Petru Poni Institute of Macromolecular Chemistry | And 4 more authors.
Bioorganic and Medicinal Chemistry | Year: 2014

An amine group was synthesized starting from an optically active bicyclo[2.2.1]heptane compound, which was then used to build the 5 atoms ring of a key 6-chloropurine intermediate. This was then reacted with ammonia and selected amines obtaining new adenine- and 6-substituted adenine conformationally constrained carbocyclic nucleoside analogues with a bicyclo[2.2.1]heptane skeleton in the sugar moiety. X-ray crystallography confirmed an exo-coupling of base to the ring and a L configuration of the nucleoside analogues. The compounds were tested for anticancer activity. © 2013 Published by Elsevier Ltd. All rights reserved.


PubMed | Central Laboratory for Phytosanitary Quarantine, Organic Chemistry Center Cdnenitescu, Petru Poni Institute of Macromolecular Chemistry, Romanian National Institute for Chemical Pharmaceutical Research and Development and Montpellier University
Type: Journal Article | Journal: Bioorganic & medicinal chemistry | Year: 2013

An amine group was synthesized starting from an optically active bicyclo[2.2.1]heptane compound, which was then used to build the 5 atoms ring of a key 6-chloropurine intermediate. This was then reacted with ammonia and selected amines obtaining new adenine- and 6-substituted adenine conformationally constrained carbocyclic nucleoside analogues with a bicyclo[2.2.1]heptane skeleton in the sugar moiety. X-ray crystallography confirmed an exo-coupling of base to the ring and a L configuration of the nucleoside analogues. The compounds were tested for anticancer activity.


Tanase C.,Romanian National Institute for Chemical Pharmaceutical Research and Development | Cocu F.G.,Romanian National Institute for Chemical Pharmaceutical Research and Development | Caproiu M.T.,Romanian Academy of Sciences | Draghici C.,Romanian Academy of Sciences | And 3 more authors.
Revista de Chimie | Year: 2010

Novel O2 -pyrimidine nucleosides with a functionalizedbicyclo[2. 2.1]heptan sugar moiety were synthesized startingfrom a pure optically active alcohol (4). This alcohol was coupled by Mitsunobu reaction to pyrimidine bases: N4-benzoylcytosine, 5-fluorouracil and N3-benzoyl- thymine, then the ester protected nucleosides were debenzoylated to the coresponding carbocyclic nucleosides, which looks to be Winked compounds. The compounds were characterized by IR, MS, 1H-NMR and 13C-NMR spectra. The preliminary in vitro preclinical results show that ent-27-5-FU (13) and ent-27-T (19) present cytotoxic or cytototxic activity in Jurkat lymphoblasts and/or U937 monocytic blasts.


Tanase C.I.,Romanian National Institute for Chemical Pharmaceutical Research and Development | Draghici C.,Organic Chemistry Center Cd Nenitescu | Caproiu M.T.,Organic Chemistry Center Cd Nenitescu | Pintiue L.,Romanian National Institute for Chemical Pharmaceutical Research and Development | And 2 more authors.
Revista de Chimie | Year: 2014

The Grignard reaction of 2-bromomagnesium ethanol-TBDMS-ether 3 with the ketone: ((1S,2S,4S,7R)-2-Chloro-5-oxobicyclo[2.2.1]heptan-7-yl)methyl methanesulfonate, 5, gave no addition to the ketone group. Instead, the basicity of organomagnesium compound 3 induce a dehydrochlorination followed by substitution of the mesyl group with bromide to the tricyclic compound 9. The intermediate bromide 8, resulted from substitution of the mesyl group of the starting compound 5, was also isolated. The oximes, acetylated oximes and 2,4-dinitrophenyl-hydrazone of compound 9 were also synthesized to characterize the final product.


Enache C.,Central Laboratory for Phytosanitary Quarantine | Enache C.,Romanian Academy of Sciences | Filip P.,Central Laboratory for Phytosanitary Quarantine | Filip P.,Romanian Academy of Sciences | And 2 more authors.
Revista de Chimie | Year: 2010

The amount of PEG contained in several commercial matrices was determined by HPLC coupled with mass spectrometry, using the external standard calibration method. The procedure is rapid and easy enough to apply. It allows as well the detection ofethyleneglycol content in the products containing PEG, if required.

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