Additionsreaktionen von 3-Dimethylamino-2,2-dimethyl-2H-azirin an Isothiocyanate

Addition Reactions of 3-Dimethylamino-2, 2-dimethyl- 2 H-azirine and Isothiocyanates. The title azirine readily reacts with two molecules of benzyl- or methylisothiocyanate to form the zwitterionic 1:2 addition compounds 4 and 13 , respectively (Scheme 2). The presumed 1:1 addition products, which are intermediates in the formation of 4 and 13 , cannot be detected. The structure of 4 and 13 follows from their spectroscopic and chemical properties. With water they give the thiourea derivates 5 and 14 , respectively; treatment with aqueous acid leads to the Δ²-1, 3-thiazolin-5-on-derivates 7 and 15 , respectively. With sodium borohydride compounds 8 and 16 , respectively, are obtained (Scheme 2). The zwitterionic compounds 4 and 13 are able to react further with one molecule of the isothiocyanates to give, in high-yield, triazines 9 and 18 , respectively (Scheme 3). The structure of these compounds was again derived from their spectroscopic data. The mechanism for the formation of 9 and 18 is given in Scheme 3. Acid catalysed hydrolysis of 9 and 18 lead to the trithiocyanuric acid derivates 12 and 20 , and to the spiro compounds 11 and 19 , respectively (Sceme 6). Reaction of 4 with one molecule of phenylisocyanate gives triazine 10 (Scheme 5). According to the X-ray analysis of the methyl compound 18 , there are strong steric interactions in this molecule which are due to the side chain. This is demonstrated by the small distances between C(2) … C(13), N(7) … C(11), and C(8) … C(11) (Table 4). These steric interactions, in addition, cause widening of the bond angles N(1)? C(2)? N(7) and C(9)? N(10)? C(11) (Fig.2). Furthermore, the triazine ring is no longer planar. This deformation of the ring diminishes repulsion between the methyl groups C(13) and C(15).     

Additionsreaktionen an der alicyclischen Doppelbindung von Eburnamenin und Apovincamin

Addition reactions on the alicyclic double bond of eburnamenine and apovincamine The addition of alcohols, amines or thiols on the 14, 15-double bond of (?)-eburnamenine ( 3a ) or (+)-apovincamine ( 9a ) yielded the corresponding analogues of vincanol ( 5b-h ), epivincanol ( 7b-d ), vincamine ( 10b-e ) and epivincamine ( 11b-g ) with varying stereoselctivity. The reaction was achieved by addition of hydrogenbromide at ?78° followed by nucleophilic attack, or in the (?)-eburnamenine series also by direct addition of alcohols and thiols under acidic conditions. Without exception the analogues of epivincamine ( 11a-g ) exhibited two carbonyl absorption bands in thier IR. spectra. (?)-Eburnamenine ( 3a ) was obtained from (+)-apovincamine ( 9a ) in a simple one pot reaction.     

Einige Derivate von 4-Hydroxycumarin

Ohne Zusammenfassung     

Einige neue Formen von Quecksilberbarometern

Ohne Zusammenfassung     

Synthesen mit Nitrilen, 22. Mitt.: Cyclisierende Additionsreaktionen von Malonitril an 1,4-Chinone

The reaction of quinizarine with malononitrile leads to 2-amino-5.6.11-trihydroxy-anthraceno[1.2?b]furan-3-carbonitrile (2). A reinvestigation of the so-calledMichael adducts of 1,4-benzoquinones with malononitrile has shown that 2-aminobenzofurans are formed.     

Urease VII. Einige Betrachtungen zur Bestimmungsmethode von Sumner

Ohne Zusammenfassung     

Einige Reaktionen von Phenoxy-amino-silanen mit Alkaliamiden

Zusammenfassung Es werden einige weitere Austauschreaktionen von Phenoxygegen Aminogruppen am Si-Atom mit Hilfe von (substitutierten) Alkaliamiden beschrieben. Sie sind in den Gl. (1) bis (7) niedergelegt. Dabei wird nur eine Phenoyxygruppe pro Molekül ausgetauscht, selbst bei Anwesenheit mehrerer Phenoxysilylgruppen und Anwendung eines größeren Alkaliamidüberschusses.The substitution of phenoxy by amino groups by means of alkali amides according equations (1)–(7) was feasible. However, even with several phenoxysilyl groups per molecule and an excess of alkali amide it was not possible to replace more than one phenoxy group.72. Mitt.:U. Wannagat, P. Schmidt undM. Schulze, Angew. Chem.79, 409 (1967).Mit Auszügen aus der DissertationG. Schreiner, Techn. Hochschule Graz, 1965.     

Einige Beobachtungen zum Nullstromverhalten von Autimou-Indicatorelektroden

Ohne Zusammenfassung     

Additionsreaktionen von 2-Amino-1-azetinen mit Cyclopropenonen; Bildung von Azepinderivaten durch Ringerweiterung. Vorläufige Mitteilung

Addition Reactions of 2-Amino-1-azetines with Cyclopropenones; Formation of Azepine Derivatives by Ring Expansion Reactions The reaction of 2-amino-1-azetines of type 6 with 2,3-diphenylcyclopropenone ( 1a ) in acetonitrile leads to azetol[1,2-α]pyrroles (cf. 7 and 9 , Schemes 3 and 4) in good yield. It is remarkable that in the reaction of 6a with 1a only endo- 7 is formed. With silicagel in ether endo- 7 isomerizes to the thermodynamically more stable exo- 7 (Schemes 3 and 6). The crystal structure of the latter compound has been established by X-ray crystallography. The reaction of 6a and 2-isopropyl-3-phenyl-cyclopropenone ( 1b ) yields only one product, which isomerizes with silicagel in ether to exo- 10 (Scheme 4). The structure of exo- 10 has been determined by NMR-spectroscopy. It seems reasonable that this structure results from a nucleophilic attack of the four-membered amidine to the phenyl-substituted C-atom of 1b.     

Additionsreaktionen von 3-Dimethylamino-2,2-dimethyl-2H-azirin an Phenylisocyanat und Diphenylketen

Addition Reaction of 3-Dimethylamino-2,2-dimethyl-2H-azirine with Phenylisocyanate and Diphenylketene 3-Dimethylamino-2,2-dimethyl-2H-azirine ( 1a ) reacts with carbon disulfide and isothiocyanates with splitting of the azirine N(1), C(3)-double bond to give dipolar, fivemembered heterocyclic 1:1 adducts. In some cases, these products can undergo secondary reactions to yield 1:2 and 1:3 adducts. In this paper it is shown that the reaction of 1a with phenylisocyanate also takes place by cleavage of the N(1), C(3)-bond, whereas with diphenylketene N(1), C(2)-splitting is observed. The reaction of 1a and phenylisocyanate in hexane at room temperature yields the 1:3 adduct 2 in addition to the trimeric isocyanate 3 (Scheme 1). A mechanism for the formation of 2 is given in Scheme 5. Hydrolysis experiments with the 1:3 adduct 2 , yielding the hydantoins 4–6 and the ureas 7 and 8 (Schemes 3 and 5), show that the formation of this adduct via the intermediates d , e and f is a reversible reaction. The aminoazirines 1a and 1b undergo an addition reaction with diphenylketene to give the 3-oxazolines 14 (Scheme 8), the structure of which has been established by spectral data and oxidative degradation of 14a to the 3-oxazolin-2-one 15 (R¹ ? R² ? CH₃, Scheme 9).     

Einige Probleme der Spurenanalyse von anorganischen Materialien

Ohne Zusammenfassung     

Einige mikroanalytische Nachweise mit Hilfe von Ionenaustauschern

Ohne Zusammenfassung     

Additionsreaktionen von 2-Thiazolin-5-thionen mit Acetylenen Vorläufige Mitteilung

Addition Reactions of 2-Thiazolin-5-thiones with Acetylenes The reaction of the 2-thiazolin-5-thiones 1 and 5 , respectively, with acetylen carboxylates yields mainly 1, 4-dithiafulvenes of type 3. In the presence of the acetylenic compounds, the 1, 4-dithiafulvenes undergo an isomerization to give the corresponding 2, 3-dihydrothiophene-2-thiones 4.     

Einige analytische Eigenschaften von 1,3-Dimethyl-4,5-diaminouracil

Zusammenfassung 1,3-Dimethyl-4,5-diaminouracil (DAL) hat sich als sehr empfindliches Reagens zum selektiven Nachweis von Co²⁺-Ionen im stark alkalischen Medium einer Phosphatpufferlösung (p_H=11,20) erwiesen. Es wurden vier Additionsverbindungen von DAL mit den Zentralatomen Cd(II), Pd(II), Ni(II) und Co(II) im Verhältnis Me DAL=1 2 hergestellt. Spektrophotometrische Untersuchungen weisen darauf hin, daß bei p_H 6 bis 7 eine Komplexverbindung im Verhältnis CoDAL=12 gebildet wird.

---

Summary 1,3-dimethyl-4,5-diaminouracil (DAL) has been found to be a very sensitive reagent for the selective detection of Co²⁺ ions in strong alkaline medium of a phosphate buffer solution (p_H=11.20). Four addition compounds of DAL with the central atoms Cd(II), Pd(II), Ni(II) and Co(II) with the ratio MeDal=12 have been prepared. Spectrophotometric studies indicate that at p_H=6–7, complex compound is produced with the ratio CoDAL=12.

     

Einige Azoxyverbindungen als Reagentien zum Nachweis von Kationen

Ohne Zusammenfassung     

Metallkomplexe von Farbstoffen. X. Neue Übergangsmetallkomplexe von Anthrachinonfarbstoffen

Metal Complexes of Dyes. X. New Transition Metal Complexes of Anthraquinone Dyes The chloro-bridged compounds [(R₃P)MCl₂]₂ (M ? Pd, Pt; R ? ethyl, phenyl, n-butyl), [(Ph₃P)₂PdCl]₂(BF₄)₂, [(η⁵-C₅Me₅)MCl₂]₂ (M ? Rh, Ir), [(η⁶-p-cymene)RuCl₂]₂, react with mono- and dianions of several 9,10-anthracene-dione dyes [1-amino-9,10-anthracene-dione, Disperse Blue 19 (1-amino-4-anline-9,10-anthracene-dione), 1,4-diamino-9,10-anthracene-dione, Solventgreen 3 [1,4-bis(4′-methylaniline)-9,10-anthracene-dione], dianthrimide [1,1′-dianthraquinonylamin], 1-azo-β-naphtol-9,10-anthracene-dione, 1-anilido-o-carboxy-9,10-anthracene-dione and Quinizarin (1,4-dihydroxy-9,10-anthracene-dione)] to give N,O-, O,O- and O,N,O-chelate complexes. Copper(II)- and palladium(II) acetate and the anion of 1-aminoanthraquinone afford N,O-bischelates. Spectroscopic data are discussed. In comparision to the free anthraquinones the dye complexes show a bathochromic shift in the UV/VIS spectra. The structures of (ethyl)₃P(Cl)Pt(1-aminoanthraquinone-H⁺), (η-C₅Me₅)(Cl)Ir(1-azo-β- #naphtolanthraquinone-H⁺) and (η-C₅Me₅)Rh(1-anilido-o-carboxyanthraquinone-2 H⁺) were determined by X-ray diffraction.