Synthesis and properties of 7-hydroxy-8-phenylxanthine and its derivatives. Disproportionation to derivatives of 8-phenylxanthine and 6-amino-5-nitrosouracil

8-Phenyl, 8-(p-methoxyphenyl) and 8-(p-chlorophenyl)-7-hydroxyxanthine were synthesized by ring closure of 6-amino-5-nitrosouracil with benzaldehyde, p-methoxybenzaldehyde and p-chlorobenzaldehyde, respectively. The disproportionation of these products to the corresponding 8-phenylxanthines and 6-amino-5-nitrosouracil was studied. The dependence of the rate of the reaction on the various substituents was studied. The disproportionation reaction is inhibited by the polarophilic ethyl acetylenedicarboxylate and enhanced by phosphate.     

Synthesis and antibacterial properties of new 8-nitrofluoroquinolone derivatives

The objective of this research was the preparation of new 8-nitrofluoroquinolone models and investigation of their antibacterial properties. The work initially involved large scale preparation of the synthon 7-chloro-1-cyclopropyl-6-fluoro-8-nitro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (3), followed by introduction of substituted primary amine appendages at the C-7 position to give derivatives 9a-g, in which the amino group is appended to substituted benzenes or aromatic heterocycles, is part of a primary alpha-amino acid or just a simple primary aliphatic amine. This nucleophilic aromatic substitution step was a very simple procedure since the 8-nitro group of the above synthon facilitated the addition of weak nucleophiles at C-7. All compounds prepared were fully identified and characterized using NMR, IR, EA and MS, and were consistent with expected structures. The prepared targets and the intermediates have shown interesting antibacterial activity against gram positive and/or gram negative strains. In particular, the p-toluidine, p-chloroaniline and aniline derivatives showed good activity against S. aureus with MIC range approximately 2-5 microg/mL. In conclusion, more lipophilic groups seem to enhance activity against gram positive strains.     

Synthesis of amino acid derivatives of 7-methoxycarbonylneoflavones

A number of aminoacyl derivatives of 4-phenylcoumarin have been obtained by the condensation of N-hydroxysuccinimide esters of 7-(1-carboxyalkoxy)-4-phenylcoumarins with L-amino acids and their derivatives.Kiev Taras Shevchenko University, Chemical Faculty, 252033, Kiev, Ul. Vladimirskaya, 65, tel/fax 225 12 73. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 464–469, July–August, 1999.     

Synthesis and some properties of complexones,succinic acid derivatives

Approaches to the synthesis of complexones, succinic acid derivatives, from maleic acid and amino derivatives were considered. Acid-base properties of these complexones were studied.     

Synthesis and photoluminescence properties of 8-hydroxyquinoline derivatives and their metallic complexes

Three new 8-hydroxyquinoline derivatives, i.e. 5-[(4-styryl-benzylidene)-amino]-quinolin-8-ol (1), 5-[(4-bromo-2-fluoro-benzylidene)-amino]-quinoline-8-ol (2) and 2-[2-(9-ethyl-9H-carbazol-2yl)-vinyl]-quinolin-8-ol (3), and their metallic complexes were synthesized and identified by ultraviolet-visible (UV-Vis), ¹H nuclear magnetic resonance (¹H NMR), Fourier transform infrared spectrometer (FTIR), mass spectrometry (MS) spectra and elemental analyses. Their fluorescence properties were studied by photoluminescence, which indicated that the luminescence wavelength of 5-and 2-substitued-8-hydroxyquinoline derivatives shifted to red in comparison with that of 8-hydroxyquinoline. Meanwhile, the fluorescence lifetime of 2-[2-(9-ethyl-9H-carbazol-2yl)-vinyl]-quinolin-8-ol and its zinc complex showed long lifetime in benzene solution. __________ Translated from Chinese Journal of Organic Chemistry, 2007, 27(3): 402–408 [译自: 有机化学]     

Synthesis and properties of derivatives of 1,4-dihydropyrimidine-5-carboxylic acid

1,4-Dihydropyrimidines were synthesized by reductive dethionation of the corresponding 2-thiono-4-aryl-1,2,3,4-tetrahydropyrimidine-5-carboxylic acid derivatives, and some of their properties were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1223–1227, September, 1986.     

Synthesis and properties of derivatives of 4-aminofuroxan-3-carboxylic acid

4-Amino-3-cyanofuroxan, obtained by the oxidation of aminocyanoglyoxime, reacts with hydrazine and hydroxylamine to form the amidrazone and amidoxime respectively of 4-aminofuroxan-3-carboxylic acid. The reaction of the amidoxime with triethyl orthoformate can lead to closure of both the pyrimidine and the 1,2,4-oxadiazole ring.Latvian Institute of Organic Synthesis, Riga. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1115–1119, August, 1997.     

Synthesis of some bifunctional derivatives of 8-methylquinoline-5-carboxylic acid

Derivatives of 8-methylquinoline-5-carboxylic acid were synthesized. Alcoholysis of 8-methyl-5-cyanoquinoline gave methyl and ethyl 8-methylquinoline-5-carboxylates, which were converted to the corresponding 8-bromomethyl derivatives. The latter were used for the introduction of a methylamino group and the synthesis of N-acyl derivatives. The hydrazide, amide, and anilide of 8-methylquinoline-5-carboxylic acid were obtained as model compounds.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 785–788, June, 1982.     

Synthesis and structure determination of isomeric 7- and 8-chloro-1,5-benzodiazepine derivatives

Reaction of 4-chloro-1,2-benzenediamine with 3,3-dimercapto-1-phenyl-2-propen-1-one afforded, as expected, a mixture of 7-chloro and 8-chloro-1,3-dihydro-4-phenyl-2H-1,5-benzodiazepine-2-thione. After separation of the two components and further reaction, their structure was established by chemical degradation of 7-chloro-2-(2-diethylaminoethylthio)-4-phenyl-3H-1,5-benzodiazepine to 5-chloro-1,3-dihydro-1-methyl-2H-benzimidazol-2-one. The structure was also confirmed by single X-ray analysis of 7-chloro-2-(2-diethylaminoethylthio)-4-phenyl-3H-1,5-benzodiazepine.     

Synthesis of phenyl-substituted derivatives of decahydrophenanthridine-1, 7-dione and hexahydro-8-isoquinolone

2-Bromo-2-aroylcydohexan-1-ones were prepared by bromination of 2-aroylcyclohexan-1-ones with Nbromosucccinimide and were isomerized into 6-bromo-2-aroylcyclohexan-1-ones in attempted dehydrobromination by heating in organic solvents. The reaction of 2-benzoyldimedone with oxalyl chloride was investigated. The 2-benzoyl-3-chloro-5,5-dimethyl-2-cyclohexen-1-one obtained formed 2-benzoyl-5,5-dimethyl-2-cyclohexen-1-one in reduction with zinc activated with silver acetate. The cyclohexenone was reacted with some enaminocarbonyl compounds, yielding derivatives of decahydrophenanthridine-1,7-dione and hexahydro-8-isoquinolone.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 631–635, May, 1992.     

Synthesis and spectral-luminescent properties of 5-substituted polyaryl derivatives of barbituric acid

New substituted barbituric acid derivatives containing a 4,5,6,7-tetrahydroindole moiety have been synthesized by three-component condensation. Luminescence of crystals and solutions of the compounds synthesized have been studied; a maximum luminescence intensity and a minimum Stokes shift have been found in the 1-naphthyl derivative.     

Synthesis and cytotoxic properties of derivatives of the tert-butyl ester of 7-alkylidene-3-methyl-3-cepheme-4-carboxylic acid

Sulfones of the tert-butyl esters of 7-arylmethylene-and 7-(2-furyl)methylene-3-methyl-3-cepheme-4-carboxylic acid were obtained by the condensation of the tert-butyl ester of 3-methyl-7-oxo-3-cepheme-4-carboxylic acid with arylmethylene-and 2-furylidenetriphenylphosphoranes and subsequent oxidation of the intermediate products by meta-chloroperbenzoic acid. The combination of the tert-butyl esters of 7E-bromomethylene-and 7,7-dibromomethylene-3-methyl-1,1-dioxo-3-cepheme-4-carboxylic acids with trimethylsilylacetylene under conditions of the Sonogashira reaction gave the tert-butyl esters of 3-methyl-1,1-dioxo-7E-(3-trimethylsilyl-2-propynylidene)-3-cepheme-4-carboxylic acid and 3-methyl-1,1-dioxo-7-[1,5-bis(trimethylsilyl)-1,4-pentadiyn-3-ylidene]-3-cepheme-4-carboxylic acid. The Vilsmeier reagent was used to incorporate the dimethylaminomethylene group at C-2 of the 7Z-and 7E-isomers of the tert-butyl ester of 7-(4-chlorophenyl)methylene-3-methyl-1,1-dioxo-3-cepheme-4-carboxylic acid. The cytotoxic properties of the derivatives of the tert-butyl ester of 7-alkylidene-3-methyl-3-cepheme-4-carboxylic acid in regard to cancer and normal cells in vitro depends on the structure and 7Z-or 7E-isomerism of the substituent in the 7-alkylidene group as well as the presence of a dimethylaminomethylene group at C-2 of the 3-cepheme system.     

Synthesis of 7-oxo-8-aza-10a-homoprost-13-enoic acid

The synthesis of a prostaglandin E₁ analog, 7-oxo-8-aza-10a-homoprost-13-enoic acid, is reported.     

Synthesis and fluorescence properties of environment-sensitive 7-(diethylamino)coumarin derivatives

By linking 7-(diethylamino)coumarin and different aromatic groups via an oxazole moiety, a small series of new environment-sensitive fluorophores have been synthesized. They display varying degrees of environment-sensitivity, depending on the aromatic group present on the oxazole ring. Additionally, these coumarin-based fluorophores show considerably better photostability compared to the nitrobenzoxadiazole fluorophore, and offer a good starting point for the further development of these fluorophores into environment-sensitive membrane probes or for other applications requiring sensitivity to the environment.     

Purines. XIV. Synthesis and properties of 8-nitroxanthine and its N-methyl derivatives

Xanthine ( 1 ) and its N-methyl derivatives 2–16 have been nitrated to the corresponding 8-nitro derivatives 17–32 under different reaction conditions. Nitration in glacial acetic acid with nitric acid works well with the N-7 unsubstituted and some of the 9-methylxanthines, respectively, whereas the 7-methylxanthine derivatives react best with nitronium tetrafluoroborate in sulfolane or glacial acetic acid. The 8-nitro group can be displaced nucleophilically to form 8-chloro-, 33, 34 , 8-ethoxy-, 35,36 , and uric acid derivatives 37–40 , respectively. The newly synthesized 8-nitroxanthines have been characterized by elemental analyses, pK-determinations and uv and ¹H-nmr spectra.     

Synthesis and properties of 7-formyl-8-hydroxyquinoline and its transition metal complexes

Summary Co^II, Ni^II, Cu^II, Cd^II and Hg^II complexes of 7-formyl-8-hydroxyquinoline (HFHQ) have been prepared, and characterized by elemental analysis, molar conductivities, electronic and i.r. spectra, and magnetic measurements. It was found that the ligand acts as a neutral monodentate or a monobasic bidentate donor. The Co^II, Ni^II and Cu^II complexes possess, respectively, tetrahedral, octahedral and square-planar structures based on their magnetic and electronic spectral data. The electrical conductivities of HFHQ and its metal complexes were measured at different temperatures and their activation energies were calculated. The values obtained for the Co^II, Ni^II, Cd^II and Hg^II complexes agree fairly well with those reported for semiconductors. The ligand was tested as a corrosion inhibitor for aluminium; the limiting concentration of HFHQ to give maximum efficiency (99.2%) is 10^–3 mole dm^–3 at 22°C. The metal-ligand ratios and apparent formation constants for the species generated in ethanol solution were determined spectrophotometrically.     

Synthesis and properties of sym-triazine derivatives. 7. Synthesis of pyridyl-substituted 2-amino- and 2,4-diamino-sym-triazines

N-Substituted 2,4-diamino-6-pyridyl-sym-triazines were synthesized by cyclocondensation of pyridinecarboxylic acid esters with biguanides. 4,6-Disubstituted 2-amino-sym-triazines containing pyridyl residues were obtained by the reaction of pyridinecarboxylic acid nitriles with guanidine or of pyridinecarboxylic acid esters with N-imidoylguanidines. Aminotriazines of this type are also formed in the condensation of N-acylguanidines with nitriles or imino esters. The general principles of the fragmentation of 2-amino-4-dialkylamino-6-pyridyl-sym-triazines under the influence of electron impact were established.See [1] for Communication 6.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 674–680, May, 1988.     

Synthesis and surface-active properties of the fatty acid N-methylethylolamides and their phosphate derivatives

N-Methylethylolamides have been synthesized on the basis of vegetable oils (corn, coconut, canola, olive, cotton-seed, and palm) and modified with orthophosphoric acid. The structure of the synthesized N-methylethylolamides and their phosphate derivatives has been identified by IR and NMR spectroscopies. Surface activity of the N-methylethylolamides and their derivatives at the water–air border has been determined and their colloidal-chemical parameters (maximum surface excess concentration and minimum area per molecule at the aqueous solution–air interface, surface pressure at the critical micellization concentration (CMC), standard thermodynamic parameters of adsorption and micellization) have been calculated. The character of influence of the surfactants structure on their colloidal-chemical parameter has been clarified. The petroleum-collecting and petroleum-dispersing capacities of the synthesized surfactants have been studied on the surface of the water of various mineralization degrees.