Behaviour of Mo,Al, As,Cs, Sn,Sb, Pd,Rh, Ru,Ge, Se and Te on the macroporous resin AG MP-1 in alkaline medium

The behaviour of Mo and some other elements on Ag MP-1 in alkaline medium was investigated. Equilibrium distribution coefficients, K_d, are presented for Mo on the anion exchangers AG 1-X2, AG 1-X4, AG 1-X8 and AG MP-1, and for some elements on AG MP-1 in alkaline medium. An anion exchange chromatographic separation of Mo from some of these elements is described and some results obtained with this method are reported.     

Growth of kidney epithelial cells in hormone-supplemented, serum-free medium.

Madin Darby canine kidney cells can grow in synthetic medium supplemented with 5 factors--insulin, transferrin, prostaglandin E1, hydrocortisone and triiodothyronine--as a serum substitute. These 5 factors permit growth for one month in the absence of serum, and a growth rate equivalent to that observed in serum-supplemented medium. Dibutyryl cAMP substitutes for prostaglandin E1 in the medium, suggesting that increased growth of Maden Darby canine kidney cells results from increased intracellular cAMP. Potential applications of the serum-free medium are discussed. The medium permits the selective growth of primary epithelial cell cultures in teh absence of fibroblast overgrowth, and a defined analysis of the mechanisms by which hormones regulate hemicyst formation.     

Purines,pyrimidines, and condensed systems based on these compounds. 12. 1,3-Dimethylpyrimido[4,5-d]pyrimidine-2, 4-(1H,3H)dione: The first case of regioselective amination of condensed pyrimidines in position 2

1,3-Dimethylpyrimido[4,5-d]pyrimidine-2,4-(1H,3H)dione (l) reacts with alkylamides in liquid ammonia in the presence of an oxidizing agent such as KMnO₄ or Ag(C₅H₅N)₂MnO₄, giving 7-amino derivatives; but the interaction of (1) with methylamine gives a mixture of isomeric alkylaminated products. Subsequent hydrolysis of the 7-piperidino derivatives in an alkaline medium and then in an article medium gives 4-methylamino-2-piperidinopyrimidine with quantitative yield.For Communication 11, see [1].Rostov State University, Rostov-na-Donu 344104. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1249–1252, September, 1994. Original article submitted September 6, 1994.     

Purines,pyrimidines, and condensed systems based on them. 3. 7,8-Diaminotheophylline

By treating 8-aminotheophylline with hydroxylamine-O-sulfonic acid in aqueous alkali we have obtained 7,8-diaminotheophylline and studied its reactions with benzaldehyde, 1,2-dicarbonyl compounds, and acylating agents. We have established that in reactions with electrophiles, the N-amino group in 7,8-diaminotheophylline is more active than the amino group situated at the 8-position. An unexpected self-condensation of two molecules of 7,8-diaminotheophylline has been found in acid medium, leading to a purino[8,7-g]-7-azapteridine derivative.For Communication 2, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1398–1404, October, 1987.     

Octahydropyrrolo[4,3,2-m,n]acridine derivatives. 2. 1-Aryl-4,4,8,8-tetramethyl-2,3,4,5,7,8,9,10-octahydropyrrolo[4,3,2-m,n]-acridin-10-ones and intermediates in their synthesis

A series of 9-aroyl-3,3,6,6-tetramethyl-1,2,3,4,5,6,7,8-octahydroxanthen-1,8-diones has been prepared from arylglyoxals and dimedone in a dehydrating medium; upon heating with ammonia these compounds are converted to 1-aryl-4,4,8,8-tetramethyl-2,3,4,5,7,8,9,10-octahydropyrrolo[4,3,2-m,n]acridin-10-ones. These reactions occur via the intermediate formation of tetrahydroindole derivatives.For Communication No. 1, see Ref. [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 507–513, April, 1988.     

5-Oxo-1H-4,5-dihydro-1,2,4-benzotriazepines. Chemical behavior towards alkylating,acidic and alkaline agents

The chemical behavior of 4-methyl and 4-phenyl-5-oxo-1H-4,5-dihydro-1,2,4-benzotriazepines towards methylating and acidic agents has been investigated. The 4-methyl derivative, when treated with methyl fluorosulfonate furnished, after crystallization from water, a quaternary salt (2,4-dimethyl-5-oxo-1H-4,5-dihydro-1,2,4-benzotriazepinium fluorosulfonate), whereas from the 4-phenyl derivative, a complex mixture was obtained, which, after boiling with water, afforded 2-methylindazolone, aniline fluorosulfonate and formic acid. In acidic medium the 4-methyl derivative underwent an isomerization reaction yielding 1-imino-3-methylquinazolin-4-one, but the 4-phenyl derivative exclusively yielded products resulting from ring opening. In alkaline medium, both compounds gave hydrolytic cleavage products.     

1,2-Dinitrile polymers. I. Hompolymers and copolymers of fumaronitrile,maleonitrile, and succinonitrile

Homopolymers and copolymers of fumaronitrile, maleonitrile, and succinonitrile have been prepared by using medium high temperature free-radical initiators. Black, nonfusible but soluble polymers were obtained. The spectroscopic and chemical evidence indicated a structure containing α-pyrrolenine rings and no free nitrile groups in the fumaronitrile and maleonitrile polymers and 1-pyrroline rings and free nitrile groups in the succinonitrile polymers. The polymers possessed good thermal stability, free spin concentration of 10¹⁷–10¹⁸ spins/g, and an ac conductivity at room temperature in nitrogen of 10^?6 to 10^?8 ohm^?1 cm^?1.     

Polynuclear branched tetrazole systems. 3. Acidity of α,ω-ditetrazol-5-ylalkanes

α,ω-Ditetrazol-5-ylalkanes with 1 to 5 methylene groups in the alkyl fragment display the properties of dibasic heterocyclic NH acids with pK_a values lying in the range 3.4–6.1. The pK_a values of these compounds are in a linear dependence on the values of the dielectric permeability of the medium, on the chemical shifts of the signals of the endocyclic carbon atom, and of the carbon atom of the α-methylene group in the ¹³C NMR spectra. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 535–541, April. 2006.     

Synthese von heterocyclen. V. 1, 3, 4-thiadiazol-2 (3 H)-one

A new and highly versatile method for the synthesis of 1, 3, 4-thiadiazol-2 (3 H)ones 1 is described. Methoxy-1,3,4-thiadiazoles- 5 , which are readily available by condensation of O-methyl thiocarbazate ( 2 ) with acid derivatives 3 , undergo an efficient cleavage to 1 and methyl chloride with hydrochloric acid in an anhydrous medium. Many new 5-substituted thiadiazolones, unavailable by earlier routes, were synthesized. Preparative as well as mechanistic aspects are discussed. With the aid of ¹³C-NMR. spectroscopy, the tautomerism of 1 was studied, and the tautomeric equilibria was shown to be dependent on the nature of the substituent in the 5-position. The thiadiazolones 1 exist predominantly in the oxo form. The percentage of the hydroxy form, however, increases with strongly electron withdrawing substituents in the 5-position. A good correlation with pK^a? and σ-values was observed.     

Rearrangements of 1-oxa-2-azoles. 7. Synthesis and heterocyclization of 3-acyl-1,2,4-oxadiazole oxime

The reaction of 1,2,4-oxadiazole-3-carbonitrile oxide with 2-(ethoxycarbonylmethylene)imidazolidine gives an acyclic addition product, which cyclizes in basic medium into an isoxazole derivative, while in an acid medium it rearranges into an aminofurazan derivative.For Communication 6, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1121–1122, August, 1991.     

Stereostructure of komodoquinone A, a neuritogenic anthracycline, from marine Streptomyces sp. KS3

The absolute stereostructure of komodoquinone A (1), a neuritogenic anthracycline, which was isolated from a cultured marine Streptomyces sp. KS3, has been determined on the basis of chemical derivatization. Komodoquinone A (1) induces neuronal cell differentiation in the neuroblastoma cell line, Neuro 2A and arrests the cell cycle at the G1 phase. The effect of a solid-state medium on the production of 1 and its aglycone, komodoquinone B (2), was examined.     

Thioquinomycins A-D,novel naphthothiophenediones from the marine-derived Streptomyces sp. SS17F

Thioquinomycins A-D (1–4), four novel naphthothiophenediones were isolated from the rice-based medium of the marine-derived Streptomyces sp. SS17F. Their structures were elucidated by spectroscopic methods and HRESIMS data. The absolute configurations of all the compounds were elucidated by X-ray diffraction analysis, ECD and Mosher's method combined with ¹⁹F-NMR. Compounds 1–4 showed moderate cytotoxicity against NCI-H1975 with IC₅₀ values from 17.5 to 50?μM. In addition, compounds 1–4 also exhibited inhibitory activities against PKCα and ROCK2 protein kinase.     

Indolopyridines with a hetero atom at a position of fusion. 6. Electrophilic substitution in indolo[2,1-a]isoquinoline

Nitration, halogenation, azo coupling, aminomethylation, hydroxymethylation, and acylation reactions of indolo[2,1-a]isoquinoline in a neutral or weakly acid medium gave derivatives at the C₍₁₁₎ position (the pyrrole ring). Using nitrosation as an example, it was shown that electrophilic substitution at the benzene ring of the indole fragment can occur in a strongly acid medium.For Communication 5 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 83–89, January, 1994.     

Cadmium recovery by a sulfate-reducing magnetotactic bacterium,Desulfovibrio magneticus RS-1, using magnetic separation

Cadmium recovery by a sulfate-reducing magnetotactic bacterium, Desulfovibrio magneticus strain RS-1, was investigated. D. magneticus precipitated >95% of cadmium at an initial concentration of 1.3 ppm in the growth medium. Electron microscopic analysis revealed that D. magneticus formed electron-dense particles on its surface when cultivated in the presence of cadmium ions (Cd²⁺). Sulfide was also found in the precipitate, and the composition ratio of sulfide/cadmium was 0.7. Sixty percent of viable RS-1 cells was recovered by a simple magnetic separation revealing the removal of 58% cadmium from the culture medium.     

Miniaturized Reference Electrodes. II. Use in Corrosive,Biological, and Organic Media

In a recent paper [9] we reported the manufacturing and performance of miniaturized reference electrodes (MREs) with low sensitivity to chloride ions and pH. Here, we demonstrate the wide range applicability of a MRE based on an Ag/Ag₂S internal reference element (IRE), imbedded in a photopolymerized hydrogel of improved composition, which contains the supporting electrolyte. Exchange current density, temperature coefficient, impedance value, and the voltammetric and potentiometric use of the Ag/Ag₂S‐based MRE are discussed relative to the previously reported Ag/AgSCN, Ag/Ag₃PO₄, and Ag/AgCl‐based MREs. No special or extensive conditioning is required when moving these MREs from aqueous supporting electrolyte to an organic solution or from one organic medium to another, and the equilibration time in a new medium is very rapid (<6 min). The new Ag/Ag₂S MRE has a highly stable potential in various media, including aqueous solutions (salt buffers and 20 wt.% H₂SO₄), biological samples (bovine serum albumin), mixed aqueous‐organic, and organic supporting electrolytes (methanol, ethanol, acetonitrile, propylene carbonate, methylene chloride, and DMSO). This is particularly advantageous when in the course of the electrochemical analysis an organic solution is being added to an aqueous supporting electrolyte. Such MREs are suitable for analyses of μL sample volumes and for use in protein‐containing media.     

Chemistry of heterocyclic N-oxides and related compounds 13. Acylamination of pyridine N-oxide by aniline,p-anisidine,and their N-p-tosyl derivatives

Acylamination of pyridine N-oxide by aniline, p-anisidine, and their tosyl derivatives was carried out in an alkaline medium in the presence of p-tosyl chloride. The reaction proceeds selectively with the formation of the corresponding 2-(N-p-tosyl) anilino- and 2-p-(N-p-tosyl)anisidino-pyridines. The reaction products were converted by acid hydrolysis into the corresponding 2-anilinopyridines.For communication 12, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 936–938, July, 1986.     

Reaction of 1,3-diaryl-2,3-dibromo-1-propanones with urea in basic and acidic medium. Synthesis of pyrimidine,imidazoline and imidazolidine derivatives

Reaction of 1,3-diaryl-2,3-dibromo-1-propanones 1 with urea in basic medium afforded 4,6-diaryl-5-bromo-5,6-dihydropyrimidine-2(1H)-ones 4 . Oxidation of these bromopyrimidines 4 in dimethylsulphoxide gave 4,6-diaryl-1,6-dihydropyrimidine-2,5-diones 6 , which were further converted to their thione analogues 7 . Reaction of 1,3-diaryl-2,3-dibromo-1-propanones 1 with urea, phenylurea and sym-diphenylurea in glacial acetic acid medium gave in appreciable yields 4-phenyl-5-α-(bromoarylmethyl)imidazolin-2-one 8 and 1,3-diphenyl-4-aroyl-5-arylimidazolidin-2-one 11 respectively.     

Chemotherapeutic agents. IX. Synthesis and pesticidal activities of bis[4-aryl/alkyl-1, 2, 4-triazoline-5-thione-3-yl]alkanes and 1 -Aryl/alkyl-3-[4-(4-aryl/alkyl-1, 2, 4-triazoline-5-thione-3-yl)phenyl]thiourea and related compounds

Various bis[4-aryl/alkyl-1, 2, 4-triazoline-5-thione-3-yl]alkanes ( 3 ) were prepared from base cyclization of bis thiosemicarbazide 2 and transformed into sulphides by reaction with different alkyl halides in alkaline medium. These compounds were further oxidised to sulphones 5 with acidic potassium permanganate. 1-Aryl-3-[4-(4-aryl/alkyl-1, 2, 4-triazoline-3-thione-5-yl)phenyl]thioureas ( 8 ) were prepared in two steps from p-aminophenylhydrazide ( 6 ) and aryl/alkylisothiocyanates. Alkylation of 8 with different alkyl halides yielded exclusively sulphides 9 . Some sulphides 12 and Mannich bases 13 from 5-(p-fluorophenyl)-1, 3, 4-oxadiazol-2-thione ( 11 ) were also prepared to evaluate their pesticidal activities. All the prepared compounds were screened for pesticidal activities but none of them exhibited any significant activity.     

Nucleophilic addition to C,C double bonds. III. Chemical reactivity of 1endo, 4endo: 5exo, 8exo-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalen-10syn-ol and X-ray structure analysis of its p-nitrobenzoate

The title compound 1 is a further example of an olefinic alcohol that undergoes ether formation under basic conditions (→ 3) although the double bond is not activated by an electron-attracting group. This unusual reactivity is due to steric compression, which is increased in the 10-methyl analogue 2. This forms the corresponding ether 7 at a much higher rate. - In a deuteriated medium, base-catalysed cyclization of 1 gives the exo-deuteriated ether 6 , corresponding to trans-addition. - An X-ray structure analysis of 4 , the p-nitrobenzoate of 1 , is presented.     

Recherches sur les arǒmes. 17e communication. Sur l'arǒme de framboise,IV

The neutral fraction of medium volatility from raspberry oil has been analysed by gas chromatography and mass spectrometry. From the large number of constituents thirtynine have been identified, 24 of them for the first time, including dihydro-β-ionone (I), epoxy-β-ionone (II), damascenone (III)¹, theaspirane (IV) and 2-hexen-4-olide (V). According to these results raspberry oil consists mainly of alcohols, ketones, aldehydes and lactones.