1,2-bis(2',6'-dimethyl-i',3'-dioxa-6'-aza-2'-silacyclooctyl-2')ethane and the corresponding ethylene and acetylene derivatives

Conclusions The reaction of 1,2-bis(methyldimethoxysilyl)ethane and the corresponding ethylene and acetylene derivatives with bis(2-hydroxyethyl)methylamine gives 1,2-bis(2,6-dimethyl-1,3-dioxa-6-aza-2-silacyclooctyl-2)ethane and the corresponding ethylene and acetylene derivatives. Analogously, 1,2-bis(vinyldimethoxysilyl)acetylene gave 1,2-bis(2-vinyl-6-methyl-1,3-dioxa-6-aza-2-silacyclooctyl-2)acetylene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1420–1421, June, 1988.     

Nitration,amination, and halogenation of Di-O-methylphloracetophenone

Chlorination of the title compound gave 5- and 3-chloro-2-hydroxy-4,6-dimethoxyacetophenone. The nitration of its acetate, followed successively by reduction, diazotization, and reaction with cuprous chloride, gave the 3-substituted series, 2-acetoxy-4,6-dimethoxy-3-nitroacetophenone, 3-amino-2-hydroxy-4,6-dimethoxyacetophenone, and 3-chloro-2-hydroxy-4,6-methoxyacetophenone, respectively. The orientation of substituents in the products was proved. The amino and chloro members of the isomeric 5-substituted series were availablevia 2-hydroxy-4,6-dimethoxy-5-phenylazoacetophenone, the product of the reaction of the title compound with benzenediazonium chloride.

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Nitrierung, Aminierung und Halogenierung von Di-O-methylphloracetophenon

Zusammenfassung Chlorierung der Titelverbindung gab 5- und 3-Chlor-2-hydroxy-4,6-dimethoxyacetophenon. Die Nitrierung des Acetats, gefolgt von Reduktion, Diazotierung und Reaktion mit CuCl ergab die 3-substituierte Reihe: 2-Acetoxy-4,6-dimethoxy-3-nitroacetophenon, 3-Amino-2-hydroxy-4,6-dimethoxyacetophenon und 3-Chlor-2-hydroxy-4,6-dimethoxyacetophenon. Die Orientierung der Substituenten wird diskutiert. Die Amino- und Chlorderivate der isomeren 5-substituierten Reihe sind über 2-Hydroxy-4,6-dimethoxy-5-phenylacetophenon zugängig, dem Produkt der Reaktion der Titelverbindung mit Phenyldiazoniumchlorid.

     

Analogs of pyrimidine nucleosides

The UV absorption spectra of 5-substituted N¹-(tetrahydrofuran-2-yl)- and N¹-(2oxotetrahydrofuran-3-yl)uracils have been studied and their protolysis constants have been determined by the spectrophotometric method. A comparison is given with the spectra and pKa values of the corresponding N¹-methyl derivatives and ribosides and deoxyribosides.For part IV see [11].The work was carried out with analytical samples of compounds obtained by us previously [9–12].     

Die γ-Bestrahlung von synthetischem β-Carotin

Zusammenfassung Das feste -Carotin ist gegen -Strahlung ziemlich stabil. Bei Bestrahlung unter Sauerstoffbegasung treten deutliche -Carotin-Verluste erst bei der hohen Dosis von 12 Mrad auf; bei Bestrahlung an der Luft werden ähnliche Radiolyseerscheinungen erst durch wesentlich höhere Strahlendosen ausgelöst. Spaltungsprodukte, die bei 12 Mrad und Sauerstoffbegasung auftraten und dünnschichtchromatographisch aufgetrennt werden konnten, waren Isozeaxanthin, -Carotin-5,6-5, 6-diepoxid, -Carotin-5,8-5,8-diepoxid, -Apo-12-carotinal, -Apo-10-carotinal, 3,3,6-Trihydroxy--carotin-5,8-epoxid und Vitamin-A-Alkohol. Es ist bemerkenswert, daß ein Teil der Radiolyseprodukte (z. B. Vitamin-A₁-Alkohol, -Apo-12-carotinal und -Apo-10-carotinal) Vitamin-A-Wirksamkeit besitzt.

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The -Irradiation of synthetic -carotene. Some physico-chemical and thin-layer chromatographic studies of radiolysis products

Solid -carotene is remarkably stable to -irradiation. In an oxygen atmosphere doses as high as 12 Mrad were required to bring about significant losses of -carotene, whereas in air even larger doses had to be applied in order to effect a comparable degree of radiolysis. Cleavage products which arose in O₂ at a dose of 12 Mrad and which could be separated from each other by thin-layer chromatography were isozeaxanthin, -carotene-5,5-5,6-diepoxide, -apo-12-carotenal, -apo-10-carotenal, 3, 3, 6-trihydroxy--carotene-5,8-epoxide and vitamin A₁. It is notable that some of the radiolysis products (e.g., vitamin A₁, -apo-12-carotenal and -apo-10-carotenal) possess vitamin A activity.

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Herrn Prof. Dr.O. Hromatka zum 65. Geburtstag gewidmet.     

Chemistry of 2-hetarylbenzimidazoles. 8. Synthesis and properties of 1-methyl-2-(5′-methyl-2′-selenienyl)benzimidazole

1-Methyl-2-(5-methyl-2-selenienyl)benzimidazole was synthesized and subjected to electrophilic-substitution reactions: nitration, bromination, sulfonation, chloromethylation, formylation, and acylation. The substituent usually enters the 4 position of the selenophene ring, but nitration with acetyl nitrate leads to a mixture of 5-nitro and 4-nitro derivatives. Oxidation of 2-selenienylbenzimidazole with potassium permanganate leads to the 5-carboxy derivative, while oxidation with selenium dioxide leads to the 5-hydroxymethyl and 5-formyl derivatives.See [1] for Communication 7.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1636–1639, December, 1987.     

Spaltungen mittels Diazoniumverbindungen und Chinonimidchlorid, 2. Mitt.: Über die Reaktion von 4,4′-Dihydroxydiphenyl-äthan- und-propanderivaten mit Diazoniumsalzen und Chinonimidchlorid

Zusammenfassung 4,4-Dihydroxydiphenyl-äthan (I) und 4,4-Dihydroxydiphenyl-propan (II) geben beim Kuppeln mit p-Nitrobenzoldiazoniumchlorid die o-Kernkupplungsprodukte (III, IV, V) und reagieren mit Chinonimidchlorid nicht. Dagegen werden 2,4,6-Trimethylphenol (Mesitol), 4,4-Dihydroxy-3,5,3,5-tetramethyldiphenyl-äthan (VI) und 4,4-Dihydroxy-3,5,3,5-tetramethyldiphenyl-propan (VII) von p-Nitrobenzoldiazoniumchlorid zu 4-Hydroxy-3,5-dimethyl-4-nitroazobenzol und von Chinonimidchlorid zum 4-Hydroxy-3,5-dimethylphenolindophenol (IX) zum Teil gespalten. Der Reaktionsmechanismus wird diskutiert.Als erste Mitteilung dieser Reiho gilt: Mh. Chem.93, 1 (1962).     

Some remarks on the periodical change of the stability constants of the lanthanide complexes

The correlations between the values of the lgK (K = stability constant of the lanthanide complex) and the reciprocal of the ionic radius 1/r or the sum of the ionization potentials ₁ ³ I for the lanthanide ions were reviewed for different ligands. A straight-line relationship (lgK – lgK)/lgK vs. (1/r – 1/r)/(1/r) or vs. ( ₁ ³ I – ₁ ³ I)/ ₁ ³ I was found within the tetrads La-Nd, Gd-Ho, and Er-Lu.

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Bemerkungen zum periodischen Wechsel der Stabilitätskonstanten von Lanthaniden-Komplexen

Zusammenfassung Es wurde eine Übersicht der Korrelationen zwischen den Werten von logK (K = Stabilitätskonstante der Lanthanidenkomplexe) und den reziproken Ionenradien 1/r oder der Summe der Ionisierungspotentiale ₁ ³ I für die Lanthanidenionen für verschiedene Liganden gegeben. Dabei wurde eine lineare Korrelation für (lgK – lgK)/lgK gegen (1/r – 1/r)/(1/r) oder gegen ( ₁ ³ I – ₁ ³ I)/_1/3 I innerhalb der Tetraden La-Nd, Gd-Ho und Er-Lu aufgefunden.

     

Thioamides of 5-nitrofuran-2-carboxylic and 3-(5′-nitrofuryl-2′) acrylic acids

Phosphorus pentasulfide reacts with the amides and substituted amides of 5-nitrofuran-2-carboxylic and 3-(5-nitrofuryl-2) acrylic acids in ethyl acetate to give the corresponding thioamides. Some amides of 5-nitrofuran-2-carboxylic and 3-(5-nitrofuryl-2) acrylic acids are synthesized for the first time. Iodine oxidation of 5-nitrofuran-2-thiocarboxamide gives 3, 5-bis (5-nitrofuryl-2)-1, 2, 4-thiazole.     

Benzoylation of 1,4-diaza-1,3-butadienes: Synthesis of representatives of a new chemical class—1,2-diamino-1-chloroethylenes

Trans-N,N-dialkyl-N,N-dibenzoyl-1,2-diamino-1-chloroethylenes — the first representatives of a new chemical class — and N,N-dialkyl-N,N-dibenzoyl-1,2-diaminoethylenes were obtained by benzoylation of N,N-dialkyl-1,4-diaza-1,3-butadienes. On increase in pressure to 10,000 atm, the yields of the N,N-dibenzoylated 1,2-diamino-1-chloroethylenes increase, and those of the N,N-dibenzoylated 1,2-diaminoethylenes decrease.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2038–2041, September, 1989.     

1,4-bis(4′-hydroxy-1′,2′,5′-trimethyl-4-piperidyl)-1,3-butadiyne and its derivatives

1.4-Bis(4-hydroxy-1,2,5-trimethyl-4-piperidyl)-1.3-butadiyne has been synthesized from the individual isomers of 4-ethynyl-1,2,5-trimethyl-4-piperidol. Hydrogenation, bromination, and cleavage have given, respectively, 1,4-bis(4-hydroxy-1,2,5-trimethyl-4-piperidyl)butane, 1,4-bis(4-nydroxy-1,2,5-trimethyl-4-piperidyl)-1,2,3,4-tetrabromo-1, 3-butadiene, and 4-(1,3-butadiynyl)-1,2,5-trimethyl-4-piperidol.     

Reactivity of hydrocarbons on Fe?Cr?O catalysts

Generalized experimental data for deep and complete oxidation of hydrocarbons on Fe–Cr–O catalysts are presented with calculated kinetic parameters and reactivity of hydrocarbons.

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The effect of zinc(II) on the formation of 2,2′- and 2,3′-bipyridine complexes of [Ru2II(ttha)]2−(ttha6−=triethylenetetraminehexaacetate)

Ru2II(ttha)(H2O)2]2– (ttha6–= triethylene tetramine hexa-acetate), prepared by the reduction of the ruthenium(III) precursor, reacts with 2,2-bipyridine (2,2-bpy) in a multi-step fashion. The first 2,2-bpy equivalent (1:1) adds with bidentate chelation at one ruthenium(II) site as revealed by separate ruthenium(II)/(III) waves at 0.03 and 0.54V vs. n.h.e. A second equivalent of 2,2-bpy (1:2) is initially stored and retained as the [Zn(2,2-bpy)]2+ complex. Further addition of 2,2-bpy initiates coordination at the second ruthenium(II) site. [Ru2(ttha)-(2,2-bpy)(H2O)]2– forms a strong ion-pair with zinc(II) that is in rapid equilibrium with the Zn(H2O)62+/Zn(2,2-bpy)]2+ pool. The solubility of the ion-pair is low. The ion-pair exhibits a shifted ruthenium(II)/(III) wave at 0.60V. Higher amounts of 2,2-bpy recomplex the zinc(II), solubilizing the complex and returning the E1/2 value to 0.54V. Other ligands which either have a higher affinity for ruthenium(II) centres than for zinc(II) as bidentate donors (1,10-phenanthroline), or ligands that cannot form bidentate zinc(II) complexes [(2-methylpyrazine, 4,4-bipyridine (4,4-bpy), and 2,3-bipyridine (2,3-bpy)] do not exhibit the unusual competition by zinc(II). These ligands all add statistically to the ruthenium(II) centres forming 1:2 complexes with 1:2 stoichiometries. 1H-n.m.r. studies of the Ru(II)polyaminopolycarboxylate complexes [RuII(hedta)(H2O)]– complex, and [Ru2(ttha)(H2O)2]2– itself, reveal that substitution of 2,3-bpy at ruthenium(II) sites occurs with an initial kinetic split between the pyridyl rings of the 3- less-hindered and 2-more-hindered ring. A slower rearrangement occurs, producing the isomer of the more-hindered 2-substituted ring. A process is driven by forming a more -accepting system when ruthenium(II) binds to the 2-ring of 2,3-bpy. Understanding the unusual influence of zinc(II) on the substitution of 2,2-bpy with [Ru2(ttha)(H2O)2]2– clarifies the nature of the 1:1 complex – namely that the 2,2-bpy becomes bidentate at one ruthenium(II) centre rather than serving as a trans-bridging ligand between both ruthenium(II) centres within one [Ru2(ttha)]2– unit.     

Synthesis of some 5′-O-amino acid derivatives of uridine as potential inhibitors ofUDP-glucuronosyltransferase

Summary In an attempt to develop potential inhibitors ofUDP-glucuronosyltransferase, some 5-O-amino acid derivatives of uridine were synthesized. N-protectedL-amino acids were coupled at the 5-O-position of 2,3-O-isopropylideneuridine by esterification employing the method of symmetrical anhydrides in presence of 4-dimethylaminopyridine, 5-O-(N-benzyloxycarbonyl-O-tert.butyl-L-threonl)-23-O-isopropylideneuridine (1), 5-O-(N-tert.butyloxycarbonyl-O-benzyl-L-seryl)-2,3-O-isopropylideneuridine and (2), 5-O-(N-tert.butyloxycarbonyl-L-valyl)-2,3-O-isopropylideneuridine (3), and 5-O-(N-tert.butyloxycarbonyl-L-valyl)-2,3-O-isopropylideneuridine (4) were obtained in good yield after column chromatography on silica gel. The treatment of2 withTFA/CH₂Cl₂ (6:1) at room temperature for 30 min led to a selective removal of theBoc group without deblocking of the 2,3-O-isopropylidene group of uridine. Treatment of2 withTFA/H₂O (5:1) at room temperature for 1 h, however, released bothBoc and 2,3-isopropylidene groups. TheZ group of1 was deprotected by catalytic hydrogenolysis over 10% Pd/C/ammonium formate.

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Synthese von 5-O-Aminosäurederivaten des Uridins als potentielle Inhibitoren derUDP-Glukuronosyl-Transferase

Zusammenfassung In einem Versuch, potentielle Inhibitoren derUDP-Glukuronosyl-Transferase zu entwickeln, wurden einige 5-O-Aminosäurederivate des Uridins synthetisiert. N-GeschützteL-Aminosäuren wurden durch Veresterung mit der 5-O-Position des 2,3-isopropylidenuridins gekuppelt (Methode der symmetrischen Anhydride in der Gegenwart von 5-Dimethylaminopyridin). Solcherweise wurden 5-O-(N-Benzyloxycarbonyl-O-tert.butyl-L-threonly)-2,3-O-isopropylidenuridin (1), 5-O-(N-tert.Butyloxycarbonyl-O-benzyl-L-seryl)-2,3-O-isopropylidenuridin (2), 5-O-(N-tert.Butyloxycarbonyl-L-leucyl)-2,3-O-isopropylidenuridin (3) und 5-O-(N-tert.Butyloxycarbonyl-L-valyl)-2,3-O-isopropylidenuridine (4) nach Säulenchromatographie (Kieselgel) in guter Ausbeute hergestellt. Die Behandlung von2 mitTFA/CH₂Cl₂ (6:1) bei Zimmertemperatur (30 min) führte zu einer selektiven Abspaltung derBoc-Gruppe ohne Deblockierung der 2,3-O-Isopropylidengruppe des Uridins. Eine Behandlung von2 mitTFA/H₂O (5:1) bei Zimmertemperatur für 1 Stunde führte hingegen zur Abspaltung sowohl derBoc als auch der 2,3-O-Isopropylidengruppe. DieZ-Gruppe von1 wurde durch katalytische Hydrogenolyse auf 10% Pd/C/Ammoniumformiat abgespalten.

     

Synthesis and some properties of the methyl ester and N,N-diethylamide of 2-azido-5-phenyl-4-thiazolecarboxylic acid

The methyl ester and N,N-diethylamide of 2-azido-5-phenyl-4-thiazolecarboxylic acid were obtained by the reaction of the corresponding 4-substituted 2-hydrazino-5-phenylthiazole with NaNO₂ in acid media. IR and UV spectroscopy were used to show that the compounds synthesized retain azide form in both the crystalline state and in solution. The reaction of azides with dicarbonyl compounds gave derivatives of 2-[5-methyl-4-acetyl-or 2-[5-methyl-4-ethoxycarbonyl-1,2,3-triazol-1-yl]-5-phenylthiazole-4-carboxylic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 710–714, May, 1993.     

Synthesen mit Nitrilen, 7. Mitt.: Darstellung und Umsetzungen von 3-Cyancumarinen

Zusammenfassung Bei der Kondensation von o-Hydroxyacetophenon mit Malonsäure-dinitril in steigendem Molverhältnis entstehen vier Produkte: 3-Cyan-4-methyl-cumarin (II), 3-(1-Amino-2,2-dicyan)-äthen-4-methyl-cumarin (IV), 2H-Malonitril-3-(1-amino-2,2-dicyan)-äthen-4-methyl-benzopyran (V) sowie ein weiteres Anlagerungsprodukt mit vier Malonsäuredinitril-einheiten. 3-Cyanund 3-Acetyl-cumarine mit freier 4-Position addieren Malonsäuredinitril zum 3-Cyan- bzw. 3-Acetyl-4-[1,3,3-tricyan-2-amino-propen-(2)]-3,4-dihydro-cumarin (X und XI).Herrn Prof. Dr. et Mr.L. Zechner, Leiter der Galenischen Abteilung am Institut für Organische und Pharmazeutische Chemie der Universität Graz, zum 70. Geburtstag gewidmet.Vorgetragen beim Chemikertreffen Schweiz-Österreich, Innsbruck, Oktober 1963.     

Darstellung von 2′,3′-Dideoxy-2′-hydroxymethyl-nucleosiden

Zusammenfassung Die Synthese von geschützten 2,3-Dideoxy-2-hydroxymethyl-nucleosiden wird beschrieben. Die durch ein Mehrstufenverfahren aus Isopropylidenglycerol erhaltenen Nucleoside können als Bausteine zur Darstellung von Oligonucleotiden verwendet werden, deren 2- und 5-Positionen über eine Etherbrücke verbunden sind.

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Synthesis of 2,3-dideoxy-2-hydroxymethyl nucleosides

Summary The synthesis of protected 2,3-dideoxy-2-hydroxymethyl nucleosides is presented. The nucleosides, obtained in a multi-step procedure starting from isopropylideneglycerol, may be used as building blocks for the synthesis of 2,5-ether linked oligonucleotides.

     

Investigations in the field of complex lipids

Summary 1. The synthesis of L-(+)--oleoyl--linoleoyl--glycerylphosphorylethanolamine has been effected.2. During the investigations the following substances were isolated and characterized: L--oleoyl--glycerylphosphoryl-N-phthaloylethanolamine and L---linoleoyl--glycerylphosphoryl-N-phthanoylethanolamine.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 2, pp. 80–83, 1966     

1,1′-Disubstituted 2,2′-di(n-perfluoropropyl)-5,5′-bibenzimidazolyls

The synthesis of 4,4-di(methylamino)- and 4,4-dianilino-3,3-diaminobiphenyls is described. The condensation of the tetraaminobiphenyls mentioned with phenyl perfluorobutyrate has given, respectively, 1,1-dlmethyl- and 1,1-diphenyl-2,2-(n-perfluoropropyl)-5, 5-bibenzimidazolyls. A study of the thermal stability of the 2-perfluoroalkylbenzimidazoles has shown that the replacement of the hydrogen of the imino group in these compounds by a methyl or a phenyl radical considerably increases their heat stability.