Zur Konfiguration von zwei isomeren rac.-Cassansäure-Derivaten.3. Mitteilung über Cassain-Analoga

Catalytic hydrogenation of cassenic and isocassenic acid derivatives ( 1 resp. 2 ) led to a mixture of the two isomers 3 and 4 , which could be separated. The structures of these isomers were confirmed.     

Über Chalkogenolate. LVII. Untersuchungen über Thioameisensäuren 5. Darstellung und Eigenschaften von Estern der Dithioameisensäure

Esters of the trimeric dithioformic acid [HCS(SR)]₃ were prepared by interaction of K[HCS₂] with alkyl iodides (R = CH₃, C₂H₅). Orthoesters HC(SR)₃ and di-orthoesters of the monomeric dithioformic acid were formed by reaction of formic acid with thioles (RSH mit R = CH₃, C₂H₅, CH₂C₆H₅) or dithioles (HS? (CH₂)_n? SH with n = 2, 3,4). The prepared compound were characterised by different methods.     

Über die Darstellung der Tetrachloridazide von Niob und Tantal. Die Kristallstruktur von Tantaltetrachloridazid TaCl4N3

On the Preparation of the Tetrachloride Azides of Niobium and Tantalum. The Crystal Structure of Tantalum Tetrachloride Azide TaCl₄N₃ NbCl₄N₃ and TaCl₄N₃ can be obtained by the reaction of the corresponding pentachlorides with ClN₃ or with NaN₃. TaCl₄N₃ crystallizes in the monoclinic space group P2₁/c: a = 13.63 Å, b = 8.820 Å, c = 13.20 Å, β = 112.07°; z = 8. It is dimeric in solution and in the solid state. The monomers are linked together via the αN atoms of the azide groups to form the centrosymmetric dimers. Two slightly different forms of dimers are found in the crystal structure. They differ in the angle between the azide group und the (Ta? αN)₂ ring. The vibrational spectra of NbCl₄N₃ and TaCl₄N₃ are reported.     

Zur Kenntnis der Fluoride zweiwertiger Lanthanoide. II. Über die Synthese von MLnF3 aus MLnF4

On Fluorides of Divalent Lanthanoids. II. Synthesis of MLnF₃ from MLnF₄ CsEuF₃, CsYbF₃, and RbYbF₃, which had already been prepared via reduction of the corresponding trifluorides with alkali metal, were also obtained by reducing MLnF₄ with M (M = Cs, Rb, K; Ln = Eu, Yb). No additional alkali fluoroperovskites of lanthanoids were detected either by reduction of LnF₃ or MLnF₄ with metallic Cs, Rb, or K or by other reactions, e.g. 3CsF + 2SmF₃ + Sm. It was shown that the reaction of CsF with EuF₂ (350–850°C) produced only very little CsEuF₃.     

Zur Berechnung der Aciditätskonstante von Sorbit aus der Sorbitolysenkinetik von Reaktivfarbstoffen. 4. Mitteilung über reaktionsmechanistische Untersuchungen an Reaktivfarbstoffen

The first acid dissociation constant of sorbitol is redetermined (PK_a = 13.00; 60°).     

Über Chalkogenolate. 135. Untersuchungen über Ester von Halogenoameisensäuren 3. Darstellung und Charakterisierung von Fluoro- und Bromothioameisensäurealkylestern

On Chalcogenolates. 135. Studies on Esters of Haloformic Acids. 3. Synthesis and Characterization of Alkyl Esters of Fluoro- and Bromothioformic Acid ⁿC₃H₇S? CO? F, C₂H₅S? CS? F, and ⁿC₃H₇S? CS? F have been prepared by reaction of the corresponding chloro compound with KF by use of phase transfer catalysts. The esters RS? CS? Br, where R ? C₂H₅ and ⁿC₃H₇, are formed by reaction between RSH and SCBr₂ in the presence of pyridine. The compounds have been characterized by means of diverse spectroscopic methods.     

Zur Kenntnis der neuen Phosphorsulfidphase P4S9. II. Über verschiedene Methoden zur Darstellung und über die Eigenschaften und Konstitution des P4S9

Both, reaction of red phosphorus, P₄S₃ or P₄S₇ with sulphur, and elimination of sulphur from P₄S₁₀ yield the new phosphorus sulphide phase P₄S₉. This phase exists in two modifications. The properties and constitution of the P₄S₉ phase are described.     

Über Chalkogenolate. 130. Untersuchungen über Rhodanine 1. Darstellung und Charakterisierung von Rhodanin und 5-Methylrhodanin

On Chalcogenolates. 130. Studies on Rhodanines 1. Synthesis and Characterization of Rhodanine and 5-Methyl Rhodanine The rhodanines with R ? H and CH₃ have been prepared by reaction of ammonium dithiocarbamate with the sodium salt of chloroacetic acid and 2-bromopropionic acid, respectively. The compounds have been characterized by means of spectroscopic methods.     

Über Chalkogenolate. 101. Untersuchungen über Halbester der Monothiokohlensäure. 1. Darstellung und Eigenschaften von Oxoxanthaten

On Chalcogenolates. 101. Studies on Hemiesters of Monothiocarbonic Acid. 1. Preparation and Properties of Oxoxanthates Alkyl oxoxanthates of alkali metals have been prepared by reaction of COS with the corresponding alkoxides. The reaction of ethyl oxoxanthate with methyl iodide leads to S-methyl-O-ethyl ester of monothiocarbonic acid. The oxidation of [SOC? OC₂H₅]^? ions with iodine forms bis(ethoxycarbonyl)-disulfide (S? CO? OC₂H₅)₂. The prepared compounds have been characterized with chemical and thermoanalytical methods as well as by means of electron absorption spectra, infrared spectra, ¹H-NMR spectra, and mass spectra.     

Über Chalkogenolate. LXI. Untersuchungen über Halbester der Kohlensäure. 1. Darstellung und Eigenschaften von Monomethyl- und Monoäthylcarbonaten

On Chalcogenolates. LXI. Studies on Hemiesters of Carbonic Acid. 1. Preparation and Properties of Monomethyl and Monoethyl Carbonates Monoalkyl carbonates M[O₂COR] with M = Li, Na, K, Rb, Cs, Tl, and R = CH₃, C₂H₅ were formed by reaction of CO₂ with alcoholates. The prepared compounds are investigated by different methods.     

Über Chalkogenolate. 132. Untersuchungen über Rhodanine 3. Darstellung und Charakterisierung von Thiorhodanin und 5-Methylthiorhodanin. Versuche zur Herstellung von Trithiopyruvinsäure

On Chalcogenolates. 132. Studies on Rhodanines. 3. Synthesis and Characterization of Thiorhodanine and 5-Methyl Thiorhodanine. Attempts to Prepare Trithiopyruvic Acid The reactions of rhodanine and 5-methyl rhodanine with P₄S₁₀ and with Lawesson reagent yield the title compounds, which have been characterized with electron absorption, ¹H and ¹³C NMR, infrared, and mass spectra. Attempts to synthesize trithiopyruvic acid by use of different procedures were not successful.     

Über die Darstellung von Phosphoniumsalzen aus Yliden und den freien Säuren bzw. ihren Ammoniumsalzen

The Synthesis of Phosphonium Salts from Ylids and Free Acids or Their Ammonium Salts Tetramethylphosphonium-acetate, -hydrogendiacetate, -azide, -thiocyanate, -nitrate, -sulfate, and -thiosulfate have been prepared from trimethylmethylene phosphorane and the corresponding acids or their ammonium salts, with liberation of ammonia. The reactions were conducted in inert solvents or in alcohol/water mixture and yield pure products in high yields.     

Über Chalkogenolate. 144. Darstellung und Eigenschaften von Alkalimetall-t-butyl-carbonaten,Neue Untersuchungen über Trimethylsilylcarbonate

On Chalcogenolates. 144. Synthesis and Properties of Alkali Metal t-Butyl Carbonates. Reinvestigations of Trimethylsilyl Carbonates The t-butyl carbonates M[O₂C? OC(CH₃)₃], where M = Li, Na, K, Rb, Cs, have been prepared by reaction of the corresponding t-butoxide with CO₂ and characterized by means of diverse methods. The equivalent conductivities of the [O₂C? OC(CH₃)₃]^? ion in aqueous solution have been determined and the Stokes radius, the radius of the hydrated ion, and the diffusion coefficient were calculated. The dissociation constant of t-butyl carbonic acid in water at 25°C is K_a = (1.63 ± 0.03)· 10^?8. The thermodynamic data of dissociation were calculated. New data of trimethylsilyl carbonates [O₂C? OSi(CH₃)₃]^? are given.     

Über Chalkogenolate, 83 Untersuchungen über Halbester der Trithiokohlensäure 1. Darstellung und Eigenschaften von Thioxanthaten

On Chalcogenolates. 83. Studies on Hemiesters of Trithocarbonic ACld. 1. Preparation and Properties of Thoxanthates Thioxanthates of alkli metals K[S₂C? SR] · H₂O with R = CH₃, C₂H₅, ⁿC₃H₇, ⁱC₃H₇, ^sC₄H₉, ^tC₄H₉ M[S₂C? S-ⁿC₄H₉] · H₂O with M = Na, K, Rb, Cs have been prepared by reaction of alkanethiols with OS₂ and the corresponding hydroxide. The i.r. spectra, electron absorption spectra, and ¹H-n.m.r. spectra have been assigned.     

Über die Dicyanierung der 1,4-Diaminoanthrachinone und die Reaktivität der 1,4-Diamino-9,10-dihydroanthracen-2,3-dicarbonitrile gegenüber nucleophilen Reagenzien 3. Mitteilung über Arylierungen und Heterocyclisierungen von Anthrachinonsystemen

The Dicyanation of 1,4-Diaminoanthraquinones and the Reactivity of 1,4-Diamino-9,10-dioxo-9,10-dihydroanthracene-2,3-dicarbonitriles towards Nucleophilic Reagents The reaction of 1-amino-9, 10-dioxo-4-phenylamino-9,10-dihydroanthracene-2-sulfonic acid ( 1 , R?C₆H₅) with cyanide in water yields a mixture of 1-amino-9,10-dioxo-4-phenylamino-9,10-dihydroanthracene-2-carbonitrile ( 3 , R ? C₆H₅) and 1-amino-4-(phenylamino)anthraquinone ( 4 , R ? C₆H₅) under the usual reaction conditions (Scheme 1). In dimethylsulfoxide, however, a second cyano group is introduced, and 1-amino-9,10-dioxo-4-phenylamino-9,10-dihydroanthracene-2,3-dicarbonitrile (7) is formed (Scheme 2). The cyano groups are very reactive towards nucleophiles. The cyano group in 2-position can be substituted by hydroxide and aliphatic amines (Schemes 5 and 6). The cyano group in 3-position can be eliminated by aliphatic amines and hydrazine (Scheme 7). Nucleophilic attack at the cyano C-atom of the 2-cyano group by suitable reagents leads to ring formation, yielding e.g. 2-(Δ²-1, 3-oxazolin-2-yl)-, 2-(benz[d]imidazol-2-yl)- and 2-(1H-tetrazol-5-yl)anthraquinones (Schemes 8 and 10).     

Über Chalkogenolate. 99. Untersuchungen über Monothiocarbamidsäure 1. Darstellung und Eigenschaften von Monothiocarbamaten

On Chalcogenolates. 99. Studies on Monothiocarbamic Acid. 1. Synthesis and Properties of Monothiocarbamates The monothiocarbamates , and Ba[SOC? NH₂]₂ have been prepared and characterized by means of infrared, electron absorption, and mass spectra. The existence of the free monothiocarbamic acid was ascertained.     

Über Chalkogenolate. LIII. Untersuchungen über Thioameisensäuren 1. Darstellung und Eigenschaften von Monothioformiaten und Monothioameisensäure

Na[HCOS] or [KHCOS] were prepared by hydrolysis of phenyl formate with NaHS or KHS. The monomeric monothioformic acid is formed on treatment of Na[HCOS] with 18% HCl and it can be distilled from the solution in a vakuum at ?5°C. The pale yellowish acid exists in the thiol form HCOSH and polymerizes even at 30°C. The S-methyl ester HCO(SCH₃) is formed on reaction of Na[HCOS] with methyl iodide, and the O-methyl ester HCS(OCH₃) on reaction of methyl orthoformate and H₂S in the presence of ZnCl₂ and hydroquinone. The prepared compounds were characterised by different methods.     

Über Chalkogenolate. LV. Untersuchungen über Thioameisensäuren. 3. Darstellung und Eigenschaften der Dithioameisensäure

Amorphous trimeric dithioformic acid has been prepared by interaction between an aqueous solution of K[HCS₂] and HCl(aq). After 1/2 – 1 minutes, the polymeric acid [ HCS(SH)]_X precipitates from a clear yellow solution of [HCS(SH)]₃ in N,N-dimethyl formamide or dimethyl sulfoxide. In solution (HCCl₃, H₂CCl₂), the existence of monomeric dithioformic acid has been verified. In the gaseous state [HCS(SH)]_n exists with n = 1, 2, 3. The dithioformic acid was investigated by different methods.