Reaktionen mit cyclischen Oxalylverbindungen, 26. Mitt. Cyclokondensation von 4,5-substituierten Thiophen- bzw. N-Alkylpyrrol-2,3-dionen mito-Phenylendiamin

4-Benzoyl-5-phenylthiophene-2,3-dione (1) reacts witho-phenylendiamine to give the quinoxaline derivative2 which cyclizes either to the furo[2,3-b]quinoxaline4 or to the thieno[2,3-b]quinoxaline5 depending on the reaction conditions. On the other hand, the pyrrol-2,3-diones6 ando-phenylendiamine combine yielding the pyrrolidino[2,3-b][1,5]benzodiazepine derivatives7. The structures of all compounds were confirmed by IR and¹³C NMR spectroscopic measurements based on X-ray structure determinations of4/5 (mixed crystal) as well as7 b.4/5 crystallize triclinically in the space group P1 (Nr. 2) with two molecules per cell, while7 b crystallizes monoclinically in space group P2₁/a (Nr. 14) with four molecules7 b and four moleculesDMSO per cell. The reaction pathways leading to the compounds2,4,5, and7 are briefly discussed.

Herrn em. Univ.-Prof. Dr.E. Ziegler zur Vollendung des 75. Lebensjahres mit besten Wünschen gewidmet.     

Chinazolincarbonsäuren, 5. Mitt.: Synthese von 1,4-Dihydro-chinazolin-4-on-1-yl-essigsäuren und Estern

1,4-Dihydro-quinazoline-4-on-1-yl-acetic acids5 were prepared by reaction of 3,1-benzoxazine-2,4-diones1 with ammonia to2. Cyclisation of2 gave4 and their hydrolysis lead to5. 2-Substituted quinazolinones9 could be obtained by reaction of2 with acid chlorides or by reaction of1 with amidines. Quinazolinone8 was synthesized in a similar way. The substituted 2-aminobenzamide10 showed a reaction behaviour different from that of2.

Dem Andenken von Dr.Wolfgang Truppe ( 24. 11. 1984) gewidmet.     

Reaktionen mit cyclischen Oxalylverbindungen,XXIV. Zur Reaktion von 4-Benzoyl-5-phenyl-furan-2,3-dion mit Phenylhydrazonen bzw. Phenylhydrazin

4-Benzoyl-5-phenyl-furan-2,3-dione (1) reacts with various phenylhydrazones2 at 60–80°C to the pyrazole carboxylic acid3 a, which then can be decarboxylated to 4-benzoyl-1,5-diphenyl-pyrazole (5).1 and phenylhydrazine combine again yielding3 a as the main product and the isomeric pyridazinone6 as by-product. At higher temperatures (120–140°C) the reaction of1 with2 a leads to the formation of dibenzoyl acetic acid hydrazide derivatives8.The structures of all products were confirmed by IR, MS,¹⁵N- and¹³C-NMR spectroscopic measurements, in the case of the pyridazinone6 also by an X-ray study.6 crystallizes with one moleDMSO monoclinically in space group P 2₁/n (Nr. 14) with 4 molecules6 andDMSO per cell.The reaction pathways leading to the compounds3, 6 and8 are discussed.

     

Studien zur Chemie von thienoanellierten O,N- und S,N-haltigen Heterocyclen, 10. Mitt.: Synthese von 2- substituierten Thieno-Diltiazemderivaten

Summary The syntheses of 2-acetyl-, 2-benzyl-, and 2-ethyl-thieno-diltiazem derivatives are described starting from the corresponding 5-substituted 3-nitro-2-thiophenthiolvia reaction with racemic methyltrans-3-(4-methoxyphenyl)-glycidate under different conditions (solvent, catalyst, temperature) to obtain purethreo orerythro products. The nitro groups of these products were reduced and the resulting amino esters cyclized. The thieno[2,3-b][1,4]thiazepin-5(4H)-ones were N-alkylated and acetylated in position 3. The desired 2-substituted 4-(2-dimethylaminoethyl)-4,5,6,7-tetrahydro-7-(4-methoxyphenyl)-5-oxothieno[2,3-b][1,4]thiazepin-6-yl acetates were isolated in good yields.

     

Synthese und Reaktionen von 2-Arylhydrazono-2-cyan-N,N-dialkyl-acetamidinen

Summary The title compounds3 were synthesized by reaction of arlyhydrazono-malononitriles1 with secondary amines and used for subsequent cyclization reactions. Thus,3 undergoes cyclooxidation by treatment with CuSO₄/pyridine to form the 5-dialkylamino-2-aryl-1,2,3-triazolo-4-carbonitriles4. From4 a and hydrazine hydrate/DMF the 4-(1,3,4-triazolyl-5)-1,2,3-triazole5 c is obtainable. The chloroacetylation of3 is accompanied by hydrolysis of the amino group to yield the arylhydrazono-N-chloracetyl cyanoacetamides6. The quaternisation of6 with pyridins is followed by the Thorpe cyclization to form the 4-amino-5-arylazo-6-hydroxy-3-pyridinio-pyrid-2-on-chlorides8, useful as cationic dyes. The reaction of3 with trichloroacetonitriles yields the 5-arylazo-4-imino-2-trichlormethyl-1,4-dihydropyrimidines10 a–c which can be converted into the 5-arylazo-2-hydrazino-pyrimidine derivatives10 d–f.From10 d the 6-phenylazo-triazolo[4,3-a]pyrimidine derivative11 is obtainable. From3 and phenylisothiocyanate the 5-arylazo-4-imino-1,4-dihydropyrimidin-2-thiones12 arise. The structures were investigated by¹³C-NMR-spectroscopy.

Herrn Prof. Dr. Fritz Sauter zum 60. Geburtstag gewidmet     

Chinazolincarbonsäuren, 10. Mitt. Synthese von 1-Methyl-2,4-dioxo-chinazolin-3-yl-essigsäure, 2,4-Dioxo-chinazolin-1-yl-essigsäuren, 2,4-Dioxo-1,3-chinazolindiessigsäuren und deren Estern

2,4-Dioxo-quinazolin-1-yl-acetic acid esters (2) were prepared by the reaction of either 3,1-benzoxazine-2,4-diones (1) with urea in the melt or in solution or of the substituted anthranilic acid ester4 with potassium cyanate in acid solution. The anthranilamides5 with trichloromethyl chloroformate (diphosgene) gave also2. Alkaline hydrolysis of2 affords the 2,4-dioxo-quinazolin-1-yl-acetic acids (3), which were independently obtained by the sequence5 6 7. 2,4-Dioxo-1,3-quinazolinediacetic acids (11) were synthesized from1 and glycine ester. Reaction of8 with ethyl chloroformate gave9 and treatment of the latter with KOH furnished the potassium salt10, which was converted to11 by acids.Quinazoline-2,4-dione (12) with ethyl bromoacetate yielded13 and with chloroacetonitrile14. 13 was hydrolyzed to11. 14 could not be converted into11.1-Methyl-3,1-benzoxazine-2,4-dione (15) was transformed under similar conditions into 1-methyl-2,4-dioxo-quinazolin-3-yl-acetic acid (16).

     

Chemie polyfunktioneller Moleküle, 126 Mitt. Synthese, Struktur und Tautomerie von 5-Fluor-N(1), N(3)-bis(diphenylphosphanyl)-uracil

Summary 5-Fluoro-uracil (1) reacts with chloro-diphenylphosphane to 5-fluoro-N(1), N(3)-bis(diphenylphosphanyl)uracil (3) which was characterized by X-ray crystallography, IR, and mass spectra.¹⁹F,³¹P{¹H},¹³C{¹H}, and¹H NMR spectra indicate that3 rearranges inTHF solution to some extent to the tautomeric 5-fluoro-O(2), O(4)-bis(diphenylphosphanyl)uracil (4). If the solvent contains traces of water, Ph₂P(O)-PPh₂ (6) and uracil derivatives are formed by hydrolysis.

Herrn Professor Dr.Walter Siebert zum 60. Geburtstag gewidmet.     

Beiträge zur Chemie der Pyrrolpigmente, 85. Mitt.: Darstellung und Lumineszenz hetero-bichromophorer Oligopyrrol-Systeme

Summary Systems consisting of a bilindione or dipyrrinone chromophore and a covalently attached, but nonconjugated, fluorescing naphthyl, anthranyl, and indolyl residue were prepared and their luminescence properties measured. Excitation energy is very effectively quenched by the dipyrrin radiationless deexcitation channel of bilins as well as by the photodiastereomerization mode of dipyrrinone fragments. A Förster type energy transfer mechanism is inferred from intermolecular Stern-Volmer kinetics in solvents of different viscosity.

     

Heterocyclensynthesen mit 5-Phenyl-isoxazoliumsalzen, 3. Mitt.: Synthese von Pyrrolo[1,2-a]chinazolin-5-onen

Refluxing of ethanol-acetic acid solutions of N-aroyl-N-methyl-benzoylacetamides3 causes elimination of acetophenone and generation of N(1)-substituted N(3)-methyl-1H,3H-quinazoline-2,4-diones5. In contrast, at room temperature in acetanhydride3 eliminate water yielding 2-benzoylmethylene-quinazolinones4, which at 60 °C cyclize to pyrrolo[1,2-a] quinazolin-5-ones6. The transformation4 6 may be explained in terms of a normalKnorr reaction. A anomalousKnorr reaction was observed in the case of the more rigid4 d leading to a mixture of diasteromere7 d cis and7 d trans in kinetically controlled reaction. Favoured by intramolecular hydrogen bonding7 d cis converts to the thermodynamically more stable6 d by warming of the ethanolic solution for 3 hours.

     

Beiträge zur Chemie der Pyrrolpigmente, 81. Mitt.: Kraftfeldrechnungen an Gallenfarbstoffen: Die Energiehyperfläche von 2,3-Dihydrobilin-1,19-dionen

Summary The energy hypersurface of 2,3-dihydrobilin-1,19-diones is analyzed with respect to their conformational aspects using a specialized force field. Estimations of helix interconversion energies, chiral discrimination, geometries of global minima, and relative energies and geometries of diastereomeres compare favourably with available experimental data from the literature.

     

Über Reaktionen mit Betain, 24. Mitt.: Über Umsetzungen von Trimethylammoniumessigsäurebetain mit reaktiven Halogenverbindungen

Summary Diethyl bromomalonate and bromoacetonitrile, respectively, react with trimethylammonium acetic acid betaine in ethanol to give diethyl tartronate and glycolic acid nitrile, respectively. By analogy, ethyl -chloroacetonate and ethyl bromopyruvate yield the respective hydroxy derivatives which were identified by their osazones2 and3. Under the same experimental conditions, mesoxalic acid and its dimethyl ester, respectively, are formed from dibromo malonic acid and its dimethyl ester and were characterized by their known hydrazones8 and9.

Herrn o. Prof. Mag. pharm. Dr. H. Junek, Karl-Franzens-Universität Graz, zur Vollendung des 60. Lebensjahres mit besten Wünschen gewidmet     

Synthese,Struktur und Reaktivität von Tris‐, Bis‐ und Mono(2,4‐dimethylpentadienyl)‐Komplexen des Neodyms,Lanthans und des Yttriums

The tris(2,4‐dimethylpentadienyl) complexes [Ln(η⁵‐Me₂C₅H₅)₃] (Ln = Nd, La, Y) are obtained analytically pure by reaction of the tribromides LnBr₃·nTHF with the potassium compound K(Me₂C₅H₅)(thf)_n in THF in good yields. The structural characterization is carried out by X‐ray crystal structure analysis and NMR‐spectroscopically. The tris complexes can be transformed into the dimeric bis(2,4‐dimethylpentadienyl) complexes [Ln₂(η⁵‐Me₂C₅H₅)₄X₂] (Ln, X: Nd, Cl, Br, I; La, Br, I; Y, Br) by reaction with the trihalides THF solvates in the molar ratio 2:1 in toluene. Structure and bonding conditions are determined for selected compounds by X‐ray crystal structure analysis and NMR‐spectroscopically in general. The dimer‐monomer equilibrium existing in solution was investigated NMR‐spectroscopically in dependence of the donor strength of the solvent and could be established also by preparation of the corresponding monomer neutral ligand complexes [Ln(η⁵‐Me₂C₅H₅)₂X(L)] (Ln, X, L: Nd, Br, py; La, Cl, thf; Br, py; Y, Br, thf). Finally the possibilities for preparation of mono(2,4‐dimethylpentadienyl)lanthanoid(III)‐dibromid complexes are shown and the hexameric structure of the lanthanum complex [La₆(η⁵‐Me₂C₅H₅)₆Br₁₂(thf)₄] is proved by X‐ray crystal structure analysis.     

Synthesen in der Isocamphanreihe, 39. Mitt.: Verbesserung derDiels-Alder-Reaktion von Cyclopentadien mit Mesityloxid durch Ultraschall und eine neue Synthese von Dehydrocamphen

Summary The synthesis of the valuable terpenic synthon 2-acetyl-3,3-dimethylbicyclo[2.2.1]hept-5-ene is clearly improved concerning the yield and especially the reaction time by applying ultrasound on theDiels-Alder reaction of cyclopentadiene with mesityl oxide. A new synthesis of dehydrocamphene and its odour impression is described.

     

Ein,altes‘ Rhodiumsulfid mit überraschender Struktur: Synthese,Kristallstruktur und elektronische Eigenschaften von Rh3S4

An ‘old' Rhodiumsulfide with surprising Structure – Synthesis, Crystal Structure, and Electronic Properties of Rh₃S₄ The reaction of rhodium with rhodium(III)‐chloride and sulfur at 1320 K in a sealed evacuated quartz glass ampoule yields silvery lustrous, air stable crystals of the rhodiumsulfide Rh₃S₄. Although a sulfide of this composition was described in 1935 a closer characterization has not been undertaken. Rh₃S₄ crystallizes in a new structure type in the monoclinic space group C2/m with a = 1029(2) pm, b = 1067(1) pm, c = 621.2(8) pm, β = 107.70(1)°. Besides strands of edge‐sharing RhS₆ octahedra which are connected by S₂ pairs (S–S = 220 pm), the crystal structure of Rh₃S₄ contains Rh₆ cluster rings in chair conformation with Rh–Rh single bond lengths of 270 pm. Both fragments are linked by common sulfur atoms. Extended Hückel calculations indicate bonding overlap for both S–S‐ and Rh–Rh‐interactions. Rh₃S₄ has a composition between the neighboring phases Rh₂S₃ and Rh₁₇S₁₅ and the structure combines typical fragments of both: RhS₆‐octahedra from Rh₂S₃ and domains of metal‐metal bonds as found in Rh₁₇S₁₅. Rh₃S₄ is a metallic conductor, down to 4.5 K the substance shows a weak, temperature independent paramagnetism.     

Studien zur Chemie von O,N- und S,N-haltigen Heterocyclen, 14. Mitt. Tricyclische 1,5-Benzothiazepine aus 2,3-Dihydro-1,5-benzothiazepin-4-amin

Summary Starting from 2,3-dihydro-1,5-benzothiazepin-4-amine (1) tricyclic 1,5-benzothiazepines were obtained. Reaction with ethyl bromopyruvat and ethyl aminoacetate hydrochloride led to the imidazo[2,1-d][1,5]benzothiazepines3 and6, respectively. The triazolo derivative8 was prepared by treatment of1 with triethyl orthoacetate/ammonia, followed by oxidative cyclization with sodium hypochlorite.

     

Strukturen der Alkalimetallsalze aromatischer,heterocyclischer Amide: Synthese und Struktur von Kronenether‐Addukten der Alkalimetall‐indolide

Structures of Alkali Metal Salts of Aromatic, Heterocyclic Amides: Synthesis and Structure of Crown Ether Adducts of the Alkali Metal Indolides The synthesis of five alkali metal indolide crown ether complexes is reported. Lithium‐indolide(12‐crown‐4) ( 1 ) was synthezised from butyllithium, indole, and 12‐crown‐4; sodium‐indolide(15‐crown‐5) ( 2 ) from sodium metal, indole, and 15‐crown‐5; potassium‐indolide(18‐crown‐6) ( 3 ) from potassium hydride, indole, and 18‐crown‐6. Rubidium‐ and cesium‐indolide(18‐crown‐6) ( 4 , 5 ) were made from Rb‐ and Cs‐hexamethyldisilazide, indole, and 18‐crown‐6. The structures of 2 , 4 , and 5 could be determined by X‐ray diffraction. The complexes 2 and 4 are mononuclear, the indolide anion shows an η¹(N)‐coordination to the metal cation. Complex 5 is dinuclear with a central [Cs—N—]₂‐ring.     

Substituenteneffekte in den13C-NMR-Spektren von diastereomeren Chalkondihalogeniden, 10. Mitt.: Erste Synthese und Konfigurationsbestimmung vonthreo-Chalkonbromhydrinen

Summary The first synthesis ofthreo chalcone bromohydrins was realized by reaction oftrans chalcone epoxides with SnBr₄ in molar ratios from 1:1 to 2:1. The compounds were obtained in high yields and isomeric purity. Their configuration was determined asthreo by different methods based on¹³C-NMR shifts of C- and C- atoms.

     

Beiträge zur Chemie der Pyrrolpigmente, 40. Mitt.: Azafulvene,Schlüsselstellen beim Aufbau von Pyrrolpigmenten? —Eine neue Synthese von verdinoiden und rubinoiden Gallenfarbstoffen

Substituted azafulvenes were generated by dehydrogenation of 5-methyl-substituted pyrromethenones withDDQ and characterized by UV- and¹H-NMR-spectroscopy. Their electrophilic properties were demonstrated using several quenchers and furthermore they were used for a synthesis of verdinoid bile pigments (which easily can be converted to rubinoid systems by the action of NaBH₄) with nearly any desired unsymmetrical alkyl substitution patter: The azafulvene spezies was generated by the action ofDDQ on a 5-methylpyrromethenone and was quenched by an 5-unsubstituted pyrromethenone. The resulting rubinoid adduct was dehydrogenated immediatly byDDQ — yields were good to high.

39. Mitt.:Falk, H., Höllbacher, G., Hofer, O., Müller, N., Mh. Chem.112, 391 (1981).