Derivate des Phosphorsäure-o-phenylenesters. XII[1]. Reaktion von Orthosäurechloriden mit Äthylenoxid

Derivatives of o-Phenylene Phosphate. XII. Reaction of Ortho-acid Chlorides with Ethylene Oxide Ortho-acid chlorides react with ethylene oxide in dependence of their structure either to ortho-acid β-chloroethylester or by splitting off 1,2-dichloroethane to the corresponding carbonyl- and phosphoryl derivatives, respectively. Using this method i. a. pentacovalent P-derivatives (pentaoxyphosphoranes 14, 16 ) are available.     

Thiatriazole. VII. 3-Aroxy-5-imino-1,2,4-dithiazole aus 5-Amino-1,2,3,4-thiatriazol

Thiatriazoles. VII. 3-Aroxy-1,2,4-dithiazole-5-imids of 5-Amino-1,2,3,4-thiatriazole The unstable but isolable 3-aroxy-1,2,4-dithiazole-5-imids ( 2a – d ) has been found on chlorothioformate acylation of 5-amino-1,2,3,4-thiatriazole ( 1 ) in acetonitril. Further acylation and nucleophilic displacement reactions gave stable 3-amino-5-acylimino-1,2,4-dithiazoles ( 6a – c , 7 ). The structure of the prepared compounds was inferred from their ¹H and ¹³C-n.m.r., mass spectra and corroborated by comparison with the data of similar derivates as well as by chemical means.     

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.     

Cyclisierungen mit 1-Nitro-2-anilino-äthylenen

Cyclizations with 1-nitro-2-anilino-ethylenes The reaction of 1-nitro-2-anilino-2-methylthio-ethylenes 1 with oxalyl chloride yields the substituted 4-nitropyrrol-2,3-diones 4 , and with chlorocarbonyl-sulfenylchloride the 5-nitro-thiazolones 6 . The methylthio group from 6 can be exchanged by amines. From 1-nitro-2,2-bis(anilino)ethylenes 2 – available from 1-nitro-2,2-bis(methylthio)-ethylene and anilines – and the same reagents, the substituted 2-nitromethylene-imidazolidine-4,5-diones 5 and the thiazolo[4,5-d]thiazoledione 9 result. The condensation of 1-nitro-2-anilino-2-hydrazino-ethylene 3 with derivatives of carboxylic acids yields 2-nitromethyl-s-triazole 12 , with diacetyl the substituted 3-nitromethylene-as-triazine 13 .     

Tetrazolverbindungen. 1. 1-Aryl-5-(2-dialkylamino-vinyl)-1H-tetrazole aus 3-Chlor-propen-iminiumsalzen

Tetrazole Compounds. 1. 1-Aryl-5-(2-dialkylamino-vinyl)-1H-tetrazoles from 3-Chloropropeniminium Salts 3-Chloropropeniminium salts 1 react with excess sodium azide in refluxing alcohols to give mainly 1-aryl-5-(2-dialkylamino-vinyl)-1H-tetrazoles 3 ; in minor quantities isomeric 5-aryl-1-(2-dialkylamino-vinyl)-1H-tetrazoles 4 are formed. The reaction involves splitting off N₂ and C → N migration of the aryl and dialkylaminovinyl group, respectively. A cross-over experiment indicated that the rearrangement step proceeds intramolecularly. — The i.r., u.v., and n.m.r. spectroscopic data of the novel 1H-tetrazoles 3 as well as the u.v. spectra of some new starting products 1k—v are reported.     

Radikalreaktionen an N-Heterocyclen. V. EPR-Untersuchungen von Nitroxid-Radikalen substituierter 3-Anilino-1,5-diphenyl-pyrazole

Radical Reactions of N-Heterocyclic Compounds. V. ESR-Investigation of Nitroxide Radicals of Substituted 3-Anilino-1,5-diphenyl-pyrazoles The correlation of the e.s.r. splitting constants with the Hammett values for nitroxides from substituted 3-anilino-1,5-diphenylpyrazoles 1a – e and substituted 1,5-diphenyl-3-p-toluidino-pyrazoles 1f – i provides evidence for extensive interannular conjugation between the N¹-benzene ring and the pyrazole ring of these nitroxides. The conjugation between the arylamino group and the pyrazole ring is extensive only in the nitroxides derived from 1f – i . The captodative substituted p-toluidino-nitroxides 2g, h have a better spin distribution than the nitroxide 2i with two electron-donating substituents.     

[3+2] Cycloaddition of Propargylamines and α‐Acylketene Dithioacetals: A Synthetic Strategy for Highly Substituted Pyrroles

A new [3+2] cycloaddition strategy for the direct synthesis of highly substituted pyrroles from the readily available α‐acylketene dithioacetals (or related substrates) and commercially available propargylamines under mild metal‐free conditions has been developed. In this reaction, the acyl group plays a critical role in driving the conjugate addition of propargylamine and further cyclization to give pyrroles. Furthermore, the wide scope was confirmed by the preparation of 1,2,3,4‐tetrasubstituted pyrroles (60–70% yields) via a formal 1,2‐acyl migrating [3+2] cycloaddition pathway with N‐methylprop‐2‐yn‐1‐amine as the secondary amine component.     

Electrochemistry of Organic Cations. VI. Investigations about the Cathodic Cleavage of Some Pyridinium and Triazolium Ions

The electrochemical reduction of some N-acylamino-, N-amino-, N-benzyl- and N-phenacyl-substituted pyridinium and triazolium ions is investigated in acetonitrile by voltammetric methods and potentiostatic electrolyses. The acylaminopyridinium ions 1 and the arylaminopyridinium ions 3 are cathodically cleaved into the pyridine derivative and the carboxylic amide or the aromatic amine. In the case of the 1-benzyl-4-acylaminotriazolium ions 5 the reductive formation of hydrogen from the acidic N-acylamino group is preferred and the corresponding ylide is formed, which reacts at more negative potential by splitting off the benzyl group. The reduction of the N-phenacylpyridinium ion 7d occurs with splitting off the phenacyl radical, which dimerizes to 1,2-dibenzoylethane in a good yield. In the case of N-benzyl- and N-p-cyanobenzylpyridinium ions the cathodic dimerization to the corresponding bisdihydropyridines was found, whereas the electrolysis of the N-nitrobenzylpyridinium ions occurs with cleavage of the N-substituent-bond, which is initiated by the primary formation of the nitrophenyl anion radical. It follows from electrogenerated chemiluminescence experiments that the cleavage of the cations 1 and 5 occurs with the uptake of one electron.     

Beiträge zum Reaktionsverhalten der Oxo-alkan-phosphonsäuredialkylester

Contributions towards the Reaction Behaviour of Dialkyl Oxo-alkane-phosphonates Dialkyl oxo-alkane-phosphonates react with dioles and their thio-analogues forming ketales and thioketales 1–19 of the general formula The arylhydrazones prepared from substituted diethyl oxo-alkane-phosphonates and aromatic diazonium salts can be cyclized without preliminar isolation to give the diethyl indolyl-2-phosphonates 20 . 1-Arylidene-2-oxo-propane phosphonic acid esters 22 and 23 react with ethyl β-aminocrotonate through MICHAEL addition followed by enamine formation to yield alkyl dihydropyridine-3-phosphonates 24 and 25 . I. R. data of the compounds prepared are recorded.     

Zur Kupplung von 4-substituierten 2-Pyrazolin-5-onen mit p-Chinondiiminkationen; Nachweis isokinetischer Beziehungen

On the Coupling of 4-Substituted 2-Pyrazoline-5-ones with Quinone Diimine Cations; Detection of Isokinetic Relations The temperature dependence of the rate constant k_K of the coupling reaction between pyrazoline-5-ones 1a – i and quinone diimine cations 2a , b is determined in dependence of the substituents at the coupling position (R³:  H,  NN Ar, CHAr–pyrazoline-5-one). The activation enthalpies are between 7 and 60 kJ mol⁻¹ and the activation entropies between −132 and −19 J mol⁻¹ K⁻¹. An isokinetic relation with β = 106°C is found and a rate determining combination of the carbanions of 1a – i with 2a , b is proposed. Contrary to this, the 2-pyrazolin-5-ones 1j – l , n (R³:  S CNH₂NR) obey an isokinetic relation with β = −45°C. Taking into consideration the activation parameters, the low dependence of k_K on the ionic strength, and the decrease of k_K with the increase of the pK values of the couplers, a rate determining splitting off of R³ is assumed.     

Seifenspaltung – kontinuierlich und umweltfreundlich

Soap Splitting – Continuous and Ecologically Harmless In the classical refining of vegetable oils the free fatty acids are saponified and separated from oil by centrifuging. The centrifuged soap solution also contains neutral oil and non hydrationable sliming substances. The resulting emulsion impedes splitting and the separation of the aqueous phase from the oily fatty acid phase. Therefore you often work with high surplus of sulphuric acid and direct vapour for heating and stirring. The direct vapour carries away fatty acid and sulphuric acid as aerosol and must be washed before drawing out into the enviroment. If the mixture from the centrifuges undergoes a saponification reaction, splitting can be continuously carried out by addition of sulphuric acid, regulated by the pH-value, without direct vapour. Thus an important requirement for an ecologically harmless procedure of soap splitting is given.     

Chemistry of methane formation in hydrogasification of aromatics. 2. Aromatics with aliphatic groups

The chemistry of the formation of methane in hydrogasification of such methyl-substituted and methylene-bridged aromatics as toluene, 1- and 2-methylnaphthalene, diphenylmethane, fluorene and 9,10-dihydroanthracene was studied using a flow tube. Temperatures varied between 600 and 1000 °C. Gases and benzene were analysed by on-line gas chromatography, the tar products being analysed by mass spectrometry. Methane formation from aliphatic groups, not in cyclic systems, is decisively favoured compared with the formation from aromatic rings. The splitting off of aliphatic groups does not influence cleavage of attached aromatic rings. Splitting off of hydrogen from the aliphatic groups weakens aromatic rings. This primary step is important for methylene bridges in five membered rings only.     

α-Substituierte Phosphonate. XXXIV. Zur Veresterung und N-Formylierung von α-Aminomethan-bisphosphonsäuren mit Orthoameisensäuretriethylester

α-Substituted Phosphonates. XXXIV. Esterification and N-Formylation of α-Aminomethane-bisphosphonic Acids with Triethylorthoformate In contrast to simple mono- and bisphosphonic acids esterification of dialkylaminomethanebisphosphonic acids with orthoformate (OAE) proceeds very slowly. Monoalkyl and monoarylaminomethanebisphosphonic acids, respectively react with OAE in constrast to analogous hydroxy compounds more readily primarily by formylating the N-atom and then esterification to formyl aminomethane bisphosphonictetraesters 10 . Acetaminomethanephosphonic acid ( 12 ) reacts without N-formylation, while the aminomethanebisphosphonic acid ( 14 ) reacted to give a mixture of mono- and bis-formylated products 15 and 16 . By acidic hydrolysis of 10 the ester- and formylgroups are splitt off, while the ester group can selectively be removed by reaction with Me₃SiBr/H₂O. – As shown by ¹H-, ¹³C- and ³¹P-n.m.r. spectroscopy the phosphorylated formamides 10 exists in two rotameres, the ratio depending on the solvent. The n.m.r. signals could be correlated to E-resp. Z-form undoubtedly by using shift-agents or the benzene-diluting technique. A rotational barrier of 22,8 kcal for 10c could be calculated.     

Cyansäureester, 27 [1]. Triazino-benzimidazole aus 2-Amino-benzimidazol-1-imidsäureestern und carbonylanalogen Verbindungen

Cyanic Acid Esters. 27. Triazino-benzimidazoles from 2-Amino-benzimidazole-1-imid-esters and Carbonyl Analogic Compounds The Cyclocondensation of 2-amino-benzimidazole-1-imid-esters with aldehydes, carbonic acid anhydrides and isocyanates has been investigated. With aldehydes in the presence of piperidine 4-aryloxy-1,2-dihydro-1,3,5-triazino[1,2-a]benzimidazoles 3 and with carbonic acid anhydrides 4-aryloxy-1,3,5-triazino[1,2-a]benzimidazoles 5 are formed. Isocyanates react with the imid esters to the corresponding 3-substituted ureas 8 which on heating undergo acyl migration of the carbamoyl group followed by cyclocondensation to 4-imino-2-oxo-1,2,3,4-tetrahydro-1,3,5-triazino[1,2-a]benzimidazoles 12 .     

Enantiomer Separation of a Novel Ca-Sensitizing Drug by simulated moving bed (SMB) – chromatography

The continuous chromatographic seperation by maens of Simulated Moving Bed (SMB) – Chromatography was used to produce the enantiomers of 5-(1,2,3,4-tetrahydroquinoline-6-yl)-6-methyl-3,6-dihydro-1,3,4-thiadiazin-2-one (EMD 53986), a precursor of the novel Ca-sensitizing drug 5-(1-(3,4-dimethoxybenzoyl)-1,2,3,4-tetrahydroquinoline-6-yl)-6-methyl-3,6-dihydro-1,3,4-thiadiazin-2-one (EMD 57033). The (+)-enantiomer EMD 57033 is a potent Ca-sensitizing drug, whereas its (−)-antipode is a pure phosphodiesterase-(PDE)-inhibitor without any Ca-sensitizing activity. A chromatographic seperation of the enantiomers was developed on two different chiral stationary phases: a cellulose-tri-(p-methyl-benzoate) phase and a polymeric silica based stationary phases. A process simulation software was used to calculate the starting parameters for the SMB-system. For both stationary phases the SBM-parameters were optimized and pure enantiomers were produced using a system with 8 columns of 26 mm internal diameter. A comparison of the purities and throughput achieved with both stationary phases is given.     

Reactions of α-Arylhydrazono-β-oxo-β-phenyl-propionitriles

ω-Cyanoacetophenone was coupled with a variety of aromatic diazonium chlorides to give the corresponding arylazo derivatives 1 a – g . Analysis of the IR and UV spectra of these compounds indicated that they exist mainly as the corresponding arylhydrazones. Compounds 1 a – d, f, g reacted with diazomethane to yield the N-methyl-arylhydrazones 2 a – f . 3-Amino-4-arylazo-5-phenylpyrazoles 5 a – g and 4-arylazo-5-imino-1,3-diphenyl-2-pyrazolines 6 a – g were obtained by the interaction of 1 a – g with hydrazine hydrate and with phenylhydrazine, respectively.     

Organophosphorus chemistry. 13 [1]. The Behaviour of 3-Aryliminoxindoles toward Alkyl Phosphites

3-Aryliminoxindoles ( 6a–c ) react with trialkyl phosphites (TAP, 2a–c ) only in presence of a protonating agent (H₂O or CH₃COOH) to give the respective dialkyl 3-(arylamino-2-oxo-1H-indol-3-yl)-phosphonates ( 9a–i ). Compounds 9 are equally obtained by reacting 6a–c with the appropriate dialkyl phosphite (DAP, 4a–c ) in absence of solvent. The role displayed by the arylimine-moiety on the reaction courses is discussed. A mechanism that accounts for formation of 9 from the reaction of anils 6 with TAP, is presented. Structural assignment are based upon analytical, chemical and spectroscopic (i.r., ¹H-n.m.r., ³¹P-n.m.r. and m.s.) results.     

New silicone rubbers, 1. Hydrophilic silicone rubbers

3-O-Allylglucose ( 1 ), allylglucoside ( 2 ) and sucrose-allylether-mixtures ( 3 ), respectively, protected by trimethylsilyl (TMS)-groups have been used as unsaturated components in crosslinking of commercially available RTV silicone components. The resulting hydrophobic silicone rubbers were converted into hydrophilic types with covalently bonded sugar residues by hydrolysis to split off the TMS-groups. Silicone rubbers with glucose residues exhibited equilibrium water contents (EWC) from 2 to 9% dependent on the molar ratio of 1 and 2 , respectively, to the Si-vinyl component. The mixtures 3 can be used as crosslinking agent without additional Si-vinyl component to give EWC's of more than 30%.     

An Energetic N‐Oxide and N‐Amino Heterocycle and its Transformation to 1,2,3,4‐Tetrazine‐1‐oxide

This study reports the preparation of 1‐amino‐1,2,3‐triazole‐3‐oxide (DPX2) and its transformation to 1,2,3,4‐tetrazine‐1‐oxide. DPX‐2 provides insight into a novel N‐oxide/N‐amino high‐nitrogen system, being the first energetic material in this class. The ability of this material to undergo a nitrene insertion forming 1,2,3,4‐tetrazine‐1‐oxide was also studied, and evidence for this material, the first non‐benzoannulated 1,2,3,4‐tetrazine‐1‐oxide, is presented. The existence of both of these materials opens new strategies in energetic materials design. DPX2 was characterized chemically (Infrared, Raman, NMR, X‐ray) and as a high explosive in terms of energetic performances (detonation velocity, pressure, etc.) and sensitivities (impact, friction, electrostatic). DPX‐2 was found to possess good thermal stability and moderate sensitivities, indicating the viability of N‐amino N‐oxides as a strategy for the preparation of new energetic materials.