Herstellung und Reaktionen von Bis-methoxyvinyl-ketonen

Synthesis and Reactions of Bis-(methoxy vinyl) ketones Bis-(methoxy vinyl carbonyl)alcane (10) are obtained by reaction of the instable bis(chloro vinyl)alcanes (9) with methanol. The products of the reaction of 10 with diamines are linear and soluble polyamides of the type of vinylen homologous polyamides 66. In the reaction of 10 with triamines insoluble polyamides are formed. These polymers are degradable by acids.     

Allgemeine Synthesen und rationelle Strukturparameter isomerer Derivate von [3,4]-kondensierten Pyrazolen

General Syntheses and Rational Parameters for Structural Assignment of Isomeric Derivatives of [3,4]-fused Pyrazoles 4 isomeric 1- or 2-methyl-, and 1- or 2-benzyl-pyrazolo[3,4-b]pyridones, i.e. the 4-oxo-types 17a, b or 11a, b and the 6-oxo-types 16a, b or 10a, b , are synthesized unambiguously. Cyclisation of 1-substituted 3- or 5-(1-methyl-2-ethoxycarbonyl-vinylamino)-pyrazoles 9a, b or. 15a, b , which were synthesized from 1-substituted 3- or 5-amino-pyrazoles and ethyl acetoacetate yields 11a, b or 17a, b in downtherm, but 10a, b or 16a, b in presence of acidic catalysts. The acidic cyclisation is preceded by a new rearrangement of 9 or 15 into 1- substituted 3- 27 or 5-amino-4-(1-methyl-2-ethoxycarbonyl-vinyl)-pyrazoles 30 ; mechanism and concurring reactions are explained. Because of their higher electron densities at C-4 it is easier to cyclise derivatives of 5-amino-pyrazoles compared to 3-amino-pyrazoles. All isomeric 1- or 2-substituted 4(6)-chloro-6(4)-methyl-pyrazolo-[3,4-b]pyridines are formed with POCl₃ from the corresponding oxo-compounds. The position of a substituent at N-1 or N-2 of [3,4]-fused pyrazoles can be assigned using the significant ¹H-n.m.r.-parameter Δ = δ — − δ_HMPT (conc. HC—3). If solvent influences are considered, δ(C  O) is a useful ¹³C-n.m.r.-parameter to distinguish the 4-oxo-types ( 11a, b; 17a, b ) from the 6-oxo-types ( 10a, b; 16a, b ) of pyrazolo[3,4-b]pyridones. Further own and lit. dates conc. structural assignment (n.m.r., i.r., u.v.) are discussed critically.     

Synthese und Reaktionen von N-Phthalimido-keten-S,S-acetalen

Synthesis and Reactions of N-Phthalimido-ketene-S,S-acetals N-substituted phthalimido derivatives 1a – f react in the presence of bases (NaH, t-BuONa) with carbon disulfide to the N-phthalimido-ketene-S,S-acetals 3 , 4 , 5 and 6 , respectively. 2-Amino-ketene-S,S-acetals 7a – c are formed by reaction of 3a , b or 5a with hydrazine hydrate. 3c produces with phenylhydrazine the pyrazole 8 , and with piperidine and pyrrolidine the E/Z mixture of the corresponding ketene-S, N-acetals 9a , b . 1c is transformed into 10a – c (E/Z-mixture)by treatment with phenylisothiocyanate under basic condition followed by alkylation.     

Organoarsen-Verbindungen. XXV. Synthese und Reaktionen von 1.3-Azarsolidin-2-thionen

Synthesis and Reactions of 1, 3-Azarsolidine-2-thiones Secondary 2-aminoethylarsines of the type RAs(H) CH₂CH₂ NHR′ react with CS₂ yielding 1,3-azarsolidine-2-thiones. Under suitable conditions the corresponding ammonium salts of the 2-arsinoethyl-dithiocarbamates are isolable as primary reaction products. 1,3-Azarsolidine-2-thiones are attacked by electrophilic agents on the sulfur atom yielding 2-alkylthio- and 2-organostannylthio-azarsolines, respectively, as well as 1,3-azarsolidine-2-ones.     

Cycloadditionen. 24. Synthese und Reaktionen von sec. N-Aryl-buta-2,3-dien-amiden

Cycloadditions. 24 Synthesis and Reactions of sec. N-Aryl-2,3-butadienamides The reaction of aryl isocyanates ( 1 ) with allenyl magnesium bromide ( 2 ) furnishes the sec. N-aryl-3-butynamides ( 4 ), which tend to tautomerize to the 2,3-butadienamides ( 5 ). Further heating of 5a – f (bearing benzoid nuclei) leads to decomposition, only 5g (bearing the naphthyl group) undergoes the expected intramolecular Diels-Alder (IMDA) reaction, leading to the benzo-tricycle ( 7g ). By reaction of a second molecule isocyanate 1 the carbomoylation of the NH moiety of 5a, c and of 3g and 4g , resp. takes place. The thereby formed N-aryl-N-butadienoyl ureas ( 9 ) either cyclize to furnish the the N-carbamoyl-2-quinolones ( 10 ) or undergo the IMDA-reaction leading to the tricyclic compounds ( 11 ). The N-butadienoyl-N-(1-naphthyl)ureas ( 12 ) only furnish the IMDA-benzo-tricycles ( 13 ).     

Darstellung und Reaktionen von 2-Arylamino-3-nitrochinolinen

Synthesis and Reactions of 2-Arylamino-3-nitroquinolines Condensation of 1-nitro-2,2-bis(methylthio)ethylene with esters of anthranilic acid yields 2-arylamino-3-nitro-4-quinolones. 2 . Analogously, from 1-nitro-2-anilino-2-methylthioethylene and o-aminoketones, 2-anilino-3-nitroquinolines 4 are obtained which can be reduced to 2-anilino-3-amino-quinolines 7 . The latter undergo cyclizations by usual methods to yield substituted triazolo-, imidazolo-, diazepino- and pyrazino-quinolines 9–12 . Reaction of ethyl-2-aminothiophene-3-carboxylates with 1-nitro-2-anilino-2-methylthio-ethylene affords 2-anilino-3-nitrothieno[2,3-b]-4-pyridones 5 .     

Darstellung,Reaktionen und spektroskopische Charakterisierung von Zweikernaromat-metall-tricarbonyl-Komplexen

Preparation, Reactions, and Spectroscopic Characterization of Di(tricarbonylmetal) Complexes of Dinuclear Arenes Di(tricarbonychromium) complexes of dinuclear arenes have been prepared by direct reaction of the dinuclear arene with hexacarbonylchromium or by an arene exchange reaction with tricarbonyl(dimethyl terephthalate)chromium. Infrared and ultraviolet spectroscopic studies show that both tricarbonylchromium groups are structural units being practically independent of each other. On the other hand, there obviously occur distinctions to the behaviour of the mononuclear complexes both during the mass spectrometric and the photolytic decay. After ultraviolet irradiation of solutions of the complexes and acrylonitrile, in tetrahydrofurane, acrylonitrile compounds of the dinuclear complexes have been detected but could not be isolated as pure substances due to their instability. Some of the prepared complexes act under hydrogenating conditions in an autoclave versus acrylonitrile as hydrogenating catalysts, but in no case as dimerizing catalysts.     

Reaktionen von Cyclanyl-Radikalen in der Gasphase. I. Cyclohexyl-Radikale aus Azocyclohexan

Reactions of Cyclanyl Radicals in the Gas Phase. I. Cyclohexyl Radicals from Azocyclohexane By theorem cyclothexyl radicals can react to yield the three isomeric C₆H₁₁-radicals: 5-hexenyl-, resonance-stabilized propyl allyl-, and cyclopentylmethyl radical. This is not sufficient a basis to explain the amount of propylene by the conversion of cyclohexenyl radicals at high temperatures. For this reason we have studied the decomposition behaviour and all other types of reactions of cyclohexyl radicals from azocyclohexane as radical source in a flow system between 400 and 480°C and in part more. The most important result is the evidence of the 3-methylcyclopentyl radical as an essential reaction intermediate.     

Heterocyclen aus Acrylnitril. I. Reaktionen von 2-Cyan-aziridin mit Ketonen

Heterocycles from Acrylonitrile. I. Reactions of 2-Cyano-aziridin with Ketones 2-Cyano-aziridine 2 is stable towards water at room temperature, but yields aziridine-2-carbonamide 6 on addition of cyclohexanone. Hemiaminal 8 is shown by ¹³C-spectroscopy to be an intermediate in this reaction. In the absence of water the aminal-like compounds 10 and 11 are formed from 2-cyano-aziridin 2 and ketones. Above 100° 2 as well as 6 form the imidazolinone 12 on action of cyclohexanone by opening of the aziridine ring and formation of a methyl group.     

Synthese und Reaktionen von 1,3-Azaphosphorinan-2-thionen

Synthesis and Reactions of 1,3-Azaphosphorinane-2-thiones Aminopropylphosphines, R P(H) (CH₂)₃ NH₂, react with carbon disulfide to give 1,3-azaphosphorinane-2-thiones. In presence of strong bases the title compounds are converted by alkyl halides into 2-alkylthio-3, 4, 5, 6-tetrahydro-1, 3-azaphosphorines whereas in absence of bases quaternization at the phosphorus atom occurs to give 2-thiono -1,3-azaphosphorinanium salts. The structures of the compounds prepared are elucidated by IR. ¹H-n.m.r. and mass spectra.     

Darstellung und Reaktionen von 2-Arylazo-2-nitro-keten-aminalen

Synthesis and Reactions of 2-Arylazo-2-nitro-keten Aminals N,N′-Disubstituted 1-nitro-2,2-diamino ethylenes 1 undergo azo-coupling to form the title compounds 2 . Their treatment with oxalyl chloride yields the imidazolidin-4,5-dione-derivatives 4. 2 react with phosgene and thiophosgene to form 6-nitro-2,4-diaryl-5-arylimino−2,3,4,5-tetrahydro-1,2,4-triazin-3-ones 5 and -thiones 6 respectively. From 2 and N-(dichloromethylene)-arylsulfoamides the 6-nitro-2,4-diaryl-5-arylimino-3-aryl-sulfonylimino-2,3,4,5-tetrahydro-1,2,4-triazines 7 arise. The reduction of 2 yields the substituted oxalic amidines 9     

Synthese von Cyclobutan durch Dehalogenierung von 1,4-Dihalogenbutanen mit Alkalimetalldämpfen. Zur Relation von radikalischen und metallorganischen Reaktionskanälen

Synthesis of Cyclobutane by Dehalogenation of 1,4-Dihalogenbutane in Alkali-Metall-Bathway. The Relation of Radical and Metallorganic Reaction-channels. Gasphase dehalogenation of 1,4-dichloro-, 1-chlor-4-bromo, 1,4-dibrombutanes and 1,4-dibrompentane by Na/K vapors produces cyclobutane resp. methylcyclobutane with selectivities of resp. 55.5, 46.7, 32.0 and 17 moles/100 moles. Side products of the reaction are ethylene and hydrogen, yields of which increase with increasing temperature and rising degree of substitution of chlorine by bromine. A mechanism is discussed in which the initiation step is the generation of halobutyl radicals of the type H₂Ċ (CH₂)₂ CH₂X (X = Cl, Br) which are reacting further in two ways – by formation of tetramethylenediradical, splitting off the second halogen atom, or by the formation of the metallorganic compound 1-kalium-4-halogenbutane, which further cyclisize to cyclobutane splitting off KX. Using some methods of theoretical chemistry such as quantumchemical calculations based on ab initio (STO-3G) and semiempirical (AM1) structures, on the relative energies of conformeres of halogenbutylradicals and on models of the metallorganic intermediates, but also by conformation calculations of the content of rotation isomers of the intermediate formed, the correlation between the two reaction channels in dependence of the type of halogen was estimated. The calculations showed, that only about 20% of cyclobutane are generated by the radical pathway. The high predominance of the metallorganic channel in the case of 1,4-dichlorbutaneis caused by the high lifetime of chlorobutyl radicals in comparison with his bromoanalogues.