Synthesis of modified amino acids containing nucleic acid purine bases

The reaction of hydrazides of adenylyl- or hypoxanthinyl-9-alkylcarboxylic acids with sodium nitrite in acid media gives reactive azides of purinyl-9-alkylcarboxylic acids which condense with ()-aminocarboxylic and ,-diaminocarboxylic acids to give N(N)-(adenylyl-9-alkanoyl) aminocarboxylic, N-(adenylyl-9-)- and N-(hypoxanthinyl-9-alkanoyl)-,-diaminocarboxylic acids. The deamination of N-(adenyl-yl-9-alkanoyl)aminocarboxylic acids gives N-(hypoxanthinyl-9-alkanoyl)aminocarboxylic acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 126–130, January, 1985.     

Reaction ofα,α-dichloro-ω-bromoalkanes andα,α-dichloro-ω-bromoalkenes with benzylmagnesium and allylmagnesium halides

Conclusions The,-dichloro--bromoalkanes and,-dichloro--bromoalkenes react with the benzyl- and allylmagnesium halides in tetrahydrofuran solution to give,-dichloroalkyl(alkenyl)benzenes,,-dichloroalkadienes in high yields. For all practical purposes the reactions do not go in ether.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 886–890, April, 1972.     

An improved method for preparing α,ω-dinitroalkanes

Summary We have suggested an improved method for preparing , -dinitroalkanes which consists in the action of silver nitrite on , -dibromoalkanes in petrofeum ether medium with heating.     

Synthesis of optically active 9-purinyl-α-amino acids

A general method for the synthesis of optically active 9-purinyl--amino acids by condensation of 5-amino-4,6-dichloropyrimidine with ,-diamino carboxylic acids and subsequent cyclization of the N-(5-amino-4-chloro-6-pyrimidinyl)-amino acids with triethyl orthoformate was developed. A number of 6-substituted -amino--(9-purinyl) carboxylic acids were obtained by nucleophilic substitution of the chlorine atom in the -amino--(6-chloro-9-purinyl) carboxylic acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1690–1695, December, 1982.     

New α,ω-diamido and α,ω-diamino mono-and bi-bridged acridine dimers

A novel set of dimers derived from 9-amino acridine was prepared and characterized by¹H and¹³CNMR. These derivatives are bridged at several different positions of the heterocyclic moieties, by the way of ,-diamido or ,-diamino side-chains. Additionally the preparation of some bi-bridged compounds was achieved.

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Neue ,-Dimaido- und ,-Diamino-Mono- und Bi-überbrückte Acridin-Dimere

Zusammenfassung Es wurde eine neue Reihe von Dimeren des 9-Aminoacridins hergestellt und mittels¹H und¹³C-NMR charakterisiert. Diese Derivate sind an verschiedenen Positionen des Heterocyclus mit ,-Diamido- oder ,-Diamino-Seitenketten überbrückt. Zusätzlich wurden auch einige zweifachüberbrückte Verbindungen hergestellt.

     

Electrochemical oxidation of tetramethyl esters of α,α,ω,ω-alcaneteracarboxylic acids

Cyclization of esters of butane-1,1,4,4- and pentane-1,1,5,5-tetracarboxylic acids during electrolysis in methanol in the presence of Nal produces, with a yield of 95%, the esters of cyclobutane-1,1,2,2- and cyclopentane-1,1,2,2-tetracarboxylic acids. Under similar conditions, esters of the highest ,,,-alkanetetracarboxylic acids undergo iodation and hydroxymethylation due to electrical oxidation of methanol to formaldehyde. During electrolysis in methanol in the presence of NaOAc, the esters of ,,,-alkanetetracarboxylic acids undergo effective hydroxymethylation, followed by cyclization into substituted five- and six-member lactones, or tetrahydrofurans when structurally possible.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2332–2339, October, 1992.     

α,ω-Bis-N-aziridinoalkanes

By reactions of ,-diamines with 1,2-dihaloethanes there were synthesized ,-bis-N-aziridinoalkanes (la-g) and bis-N-aziridinoethyl ether (II). From 1,3-diaminopropane and dichloroethane bis-aziridine (III) was isolated in addition to (Ia). NMR spectra of the products were studied.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 882–885, April, 1991.     

Complex polarizability as used to analyze dielectric relaxation measurements

The effect of representing dielectric properties in terms of the complex polarizability ^c = – i is examined. Loss curves ( and tan ) are shifted towards higher frequencies, revealing the existence of new relaxations and allowing the clarifications of ones already known. We have calculated the shift ratios (at maximum or tan )/ (at maximum or tan ) from the more conventional empirical equations representing the dielectric behavior. Some examples are given.     

Bisquaternary salts of pyrrolizidine alkaloids and their derivatives

Summary ,-Bisquaternary salts of the pyrrolizidine series have been synthesized by the reaction of ,-dibromoalkanes with some products of the cleavage of pyrrolizidine alkaloids (lindelofidine, hydroxyheliotridene, and their esters).Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 77–80, January–February, 1977.     

Fluorination of polyfluoroalkoxy derivatives of sulfur tetrafluoride by elemental fluoride

Conclusions The feasibility was demonstrated for the preparation of mono- and bis(,,-trihydro-perfluoroalkoxy) derivatives of sulfur hexafluoride by the fluorination of the corresponding sulfur tetrafluoride derivatives with elemental fluorine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1906–1908, August, 1988.     

Some transformations of α,ω-bis(1,3-thiazan-2-thion-4-on-3-yl)alkanes

The reaction of ,-bis(1,3-thiazan-2-thion-4-on-3-yl)alkanes with hydrazine gives the corresponding ,-di(4-thiosemicarbazido)alkanes, which are readily acylated. Subsequent dehydration of the acylation products gives the corresponding 5,5-dialkyl-,-bis(2,3-dihydro-1,2,4-triazole-3-thion-4-yl)alkanes, which are converted to 5,5-dialkyl- , -bis (1,2,4-triazol4-yl)alkanes by known methods. The UV and ER spectral data are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1060–1062, August, 1977.     

Reaction of 2-mercaptopyrimidines with some α,ω-dihaloalkanes

Conclusions In the reaction of some 2-mercapto-4,6-disubstituted pyrimidines with different,-dihaloalkanes, thiazolepyrimidine and pyrimidothiazine salts, 2-(-haloalkylthio)-4,6-disubstituted pyrimidines, and,-bis (4,6-disubstituted pyrimidinyl-2-thio) alkanes are formed. The structure of the products of the reactions is a function of the nature of the substituents in the pyrimidine ring, the number of methylene groups in the,-dihaloalkanes, and the ratio of the reagents.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1396–1402, June, 1984.     

Enazide, 2. Mitt.: Synthese von 1,3-Diaryl-3-azido-propenonen (α-Azidochalkonen)

Zusammenfassung Durch Kondensation von verschiedenen -Azidoacetophenonen mit aromatischen Aldehyden wurde eine Reihe von -Azidochalkonen erhalten.

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Synthesis of 1.3-diaryl-2-azido-propenones (-azido-chalcones)

Some -azido-chalcones are prepared by condensation of -azido-acetophenones with aromatic aldehydes.

     

Reactions of 2-mercaptopyrimidines with α, ω-bromochloro- and α, ω-bromofluoroalkanes

The reactions of 2-mercaptopyridines with , -bromohaloalkanes have given the corresponding haloalkylthiopyrimidines and , -bis(2-pyrimidylthio)alkanes. The IR spectra of the compounds obtained have been recorded and some of their constants have been determined.     

Synthesis of α, α, ω-trihydropolyfluoroalkyl chlorophosphates by the reaction between α,α,ω-trihydropolyfluoroalkyl phosphites and sulfuryl chloride

Conclusions An efficient method for the synthesis of ,,-trihydropolyfluoroalkyl chlorophosphates is by reacting ,,-trihydropolyfluoroalkyl dichlorophosphites and bis-(,,-trihydropolyfluoroalkyl) phosphites with sulfuryl chloride. It has been found that in three-coordinated polyfluoroalkyl phosphites, the high electronegativity of the polyfluoroalkyl groups hinders cleavage of the latter on reaction with sulfuryl chloride, thereby facilitating the formation of oxidation products.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 146–149, January, 1988.     

Dynamic shear modulus in the splitting region of poly(alkyl methacrylates)

A systematic study of the dynamic shear modulusG ^*=G+G in three poly(alkyl methacrylates) (PEMA, PnPMA, PnBMA) at frequencies between 0.001 and 500 rad/s is presented. As the splitting frequencies _s are low, aging effects can be observed in the splitting region. There is a systematic shift of the splitting frequency _s to lower values with increasing length of the alkyl side group. In PnBMA a separate shear appearance is observed about two frequency decades below the local mode . This is discussed in terms of the concept of minimal cooperativity. Aging effects are: Shift of the maximum loss frequency to lower values, peak sharpening of the relaxation, and intensity changes of and . These effects are discussed in terms of the sequential aging concept. Aging leads to a pronounced bending of the traces upwards from the equilibrium line in the Arrhenius diagram. These non-equilibrium phenomena are promoted by the small slope m=d(log )/dT of the trace in the splitting region.Dedicated to Prof. E. W. Fischer at the occasion of his 65th Birthday Lieber Herr Fischer, die Hallenser Polymerphysiker danken Ihnen aufrichtig für die warmherzige und effektive Förderung der Polymerwissenschaften im Raum Halle-Merseburg.     

Intercalation of α,ω-Alkanediamines in Layered Aluminium Dihydrogen Triphosphate Dihydrate

Intercalation of ,-alkanediamines, NH₂(CH₂) _n NH₂ (n = 3–10), into layered aluminium dihydrogen triphosphate dihydrate, AlH₂(P₃(O₁₀... 2H₂O, was investigated by XRD, DTA-TG, elemental analysis, and solid-state ³¹P, ¹³C and ²⁷Al NMR. ,-Alkanediamines are intercalated to form a monomolecular layer in the interlayer region, in which the alkanediamines incline at 57 ± 5° to the phosphate layers, whereas n-alkylamines form a bilayer structure with the same inclination angle. Two amino groups in an ,-alkanediamine molecule bridge the layered sheets of phosphates.     

Thermodynamics of Binding of α:-Cyclodextrin to Straight-Chain Alkyl Derivatives in Aqueous Solution

Apparent standard Gibbs energy, enthalpy, entropy, and heatcapacity data of the interactions of -cyclodextrin (CD) to some n-carboxylatesH(CH₂)_nCOO^- (n = 4–6), are determined by isothermal titration microcalorimetryat different temperatures in phosphate buffer, pH 9.0, assuming a 1 : 1 model indilute solution. Modelling of contributions of the thermodynamic properties of the solutionindicates that CD undergoes conformational change upon binding to homologousseries of n-carboxylates, n-alcohols, ,-alkane dicarboxylates and ,-alkane diols.     

Derivatives of 2-mercapto-6-methyluracil

The reaction of the sodium salt of 2-mercapto-6-methyluracil with , -dibromoalkanes Br(CH₂)Br (n=1,4,5,6) has given the corresponding , -bis(4-hydroxy-6-methyl-2-pyrimidinylthio) alkanes. The reaction of the same salt with 1,2-dibromoethane gave 7-methyl-5-oxo-2,3,4,5-tetrahydrothiazolo[3,2-a]pyrimidine and 5-methyl-7-oxo-2,3,4,7-tetrahydrothiazolo[3,2-a]pyrimidine, and its reaction with 1,3-dibromopropane led to 8-methyl-6-oxo-3,4,5,6-tetrahydro-2H-pyrimidino[2,1-b]-1,3-thiazine.     

Reaction of aluminum chloride with dialkylcyclosiloxanes

Summary During the reaction between aluminum chloride and cyclic dilakylsiloxanes —octamethylcyclotetrasiloxane, octaethylcyclotetrasiloxane, hexamethylcyclotrisiloxane, and hexaethylcyclotrisiloxane —ring opening occurs with the formation of -chloro--dichloroaluminoxydialkylpolysiloxanes, which further split out ,-dichloropolysiloxanes and form cyclic compounds-1-chloro-3,3,5,5-tetramethylcycloaluminoxydisiloxane and 1-chloro-3,3,5,5tetraethylcycloaluminoxydisiloxane. These compounds were separated and characterized in the form of complexes with aluminum chloride.