Gaspolarographie. II. Mitt.

Zusammenfassung Stickstoffdioxid, Stickstoffmonoxid, Distickstofftrioxid und Distickstoffmonoxid sind in wasserfreiem Dimethylsulfoxid polarographisch erfaßbar.

---

Summary Nitrogen dioxide, nitrogen, monoxide, nitrogen trioxide, and nitrous oxide can be detected polarographically in anhydrous dimethylsulfoxide.

---

Résumé On peut déceler le peroxyde d'azote, l'oxyde azotique, l'anhydride azoteux et l'oxyde azoteux par polarographie dans le diméthylsulfoxyde anhydre.

---

---

Herrn Prof. Dr.A. A. Benedetti-Pichler zum 70. Geburtstag gewidmet.

---

Für die Unterstiitzung der Untersuehungen wird der Regierung der USA gedankt.     

Oxazolochlorins. 14.

The structure of 8‐oxo‐5,10,15,20‐tetraphenyl‐7‐oxaporphyrin N²⁴‐oxide, C₄₃H₂₈N₄O₃, (4B), shows that N‐oxidation of the pyrrole opposite the oxazolidone group cants the pyrrole out of the mean plane of the chromophore. This also affects the oxazolidone group, which is also slightly canted out. This conformation is qualitatively similar to that of the parent meso‐tetraphenylporphyrin N‐oxide, but dissimilar to that of the porpholactone N‐oxide isomer 8‐oxo‐5,10,15,20‐tetraphenyl‐7‐oxaporphyrin N²²‐oxide, (4A), carrying the N‐oxide at the oxazolidone group. While the degree of canting of the N‐oxidized groups in both cases is comparable (and more pronounced than in the porphyrin N‐oxide case), in (4A) the pyrrolic groups adjacent to the N‐oxidized group are more affected than the opposing group. These differences in the conformational modes may contribute to rationalizing the distinctly different electronic properties of (4A) and (4B).     

Azole. 44.

The structure analyses of racemic 3‐chloro‐1‐(4‐morpholino‐5‐nitro­imidazol‐1‐yl)­propan‐2‐ol, C₁₀H₁₅ClN₄O₄, (II), and 3‐chloro‐1‐(5‐morpholino‐4‐nitro­imidazol‐1‐yl)­propan‐2‐ol, C₁₀H₁₅ClN₄O₄, (III), have been undertaken in order to determine the position of the morpholine residue in these two isomers. The morpholine residue in (II) is connected at the 4‐position, while in (III), it is connected at the 5‐position of the imidazole ring. The morpholine mean planes and nitro groups in the two compounds deviate from the imidazole planes to different extents. The nitro groups in (II) and (III) take part in the conjugation system of the imidazole rings. In consequence, the exocyclic C—N bonds are significantly shorter than the normal single Csp²—NO₂ bond and the nitro groups in (II) and (III) show an extraordinary stability on treatment with morpholine and piperidine [Gzella, Wrzeciono & Pöppel (1999). Acta Cryst. C 55 , 1562–1565]. In the crystal lattice, the mol­ecules of both compounds are linked by O—H?N and C—H?O intermolecular hydrogen bonds.     

Hetero-Cope-Umlagerungen. 4. Mitteilung. Regiokontrollierte Indolsynthesen

Hetero-Cope-Rearrangements, Regio-Controlled Synthesis of Indoles The reaction of O-deprotonated N-phenylhydroxylamines 1 with various electron-deficient allenes 2 , 14 , 16 gives, via Michael addition and Cope-rearrangement, substituted anilines 5 , which are easily convertible into indoles 6 . In this manner, sulfoxides 17 , serve as equivalents of 2-vinylindoles. Diels-Alder reaction with this 2-vinylindole equivalent followed by indolisation affords isoquinuclidine derivative 21 which may be a useful precursor for the preparation of Iboga alkaloids.     

Polysulfonylamines. CXXXII.

The crystal structure of the title compound, C₅H₇N₂⁺·C₁₂H₁₀NO₄S₂⁻, consists of two independent cation–anion pairs, A and B. Within each pair, the H—N—C—N*—H grouping (N*—H is the pyridinium function) and one N—S—O moiety of the anion are linked by N*—H⃛N and N—H⃛O hydrogen bonds to form an antidromic ring motif of type R²₂(8). The remaining amino donors give rise to N—H⃛O hydrogen bonds, connecting the ion pairs into A–B–A–B– chains. The structure testifies to the persistence of the R²₂(8) motif in question, which was previously detected as a highly robust supramolecular synthon in a series of onium di(methane­sulfonyl)­amidates. The structure is pseudosymmetric; the anion positions correspond to space group P2₁/n, but those of the cations do not.     

N. M. R. coupling constants

Approximate ab-initio calculations of NMR coupling constants are reported, for a number of small molecules. The agreement with experiment is erratic, and is shown to depend critically on the form of the excited state wavefunctions. This suggests that the use of an average energy approximation is far from valid.

---

Zusammenfassung NMR Kopplungskonstanten werden für eine Anzahl von kleinen Molekülen mitgeteilt, wobei sich keine rechte Übereinstimmung mit dem Experiment ergibt. Es zeigt sich, daß die Werte kritisch von der Form der Wellenfunktion für die angeregten Zustände abhängen. Das läßt vermuten, daß die Verwendung eines mittleren Energienenners nicht zu empfehlen ist.

---

Résumé Calculs ab-initio approchés des constantes de couplage NMR d'un certain nombre de petites molécules. L'accord avec l'expérience est erratique et dépend d'une façon critique de la forme des fonctions d'onde excitées. Ceci suggère que l'emploi d'une approximation d'«énergie moyenne» est loin d'être valable.

     

S.C.F.M.O. study of Hafner's hydrocarbons

SCF MO calculations have been made for Hafner's hydrocarbons using neglect of differential overlap after the manner ofPople andPariser andParr. ^* transitions have been calculated by a limited configuration interaction method. The results show that agreement between predicted spectra and observed spectra is quite good for the heptalene derivative and reasonably good for the pentalene derivative. It is suggested that both molecules are aromatic in contradiction to predictions by Craig's rule.

---

Zusammenfassung SCF MO-Rechnungen mit zero differential overlap nach der Methode vonPople, Pariser undParr wurden fürHafner's Kohlenwasserstoff angestellt. Mittels begrenzter Konfigurationswechselwirkung (wurden)die ^*-Übergänge berechnet, wobei die Ergebnisse im Fall des Heptalen-Derivates verhältnismäßig gut, in dem des Pentalen-Derivates jedoch nur ungefähr mit dem Experiment übereinstimmen. Darüber hinaus sprechen die Resultate im Gegensatz zur Craig'schen Regel dafür, daß beide Moleküle aromatischen Charakter haben.

---

Résumé Nous avons effectué des calculs SCF MO pour les hydrocarbures deHafner, en négligeant le recouvrement différentiel d'aprèsPople etPariser etParr. Quelques transitions ^* ont été calculées par interaction de configurations limitée. L'accord avec l'expérience est assez bon pour le dérivé de l'heptalène, et raisonable pour le dérivé du pentalène. Les deux molécules semblent être aromatiques, contrairement à la règle de Craig.

     

Cover Picture: Angew. Chem. Int. Ed. 7/2002

The cover picture shows Cu₂(μ‐O)₂ and Fe₂(μ‐O)₂ complexes with the M₂(μ‐O)₂ diamond core motif (the core is shown bottom right, M=green and oxygen=red spheres) and a representative example of a non‐heme multimetal enzyme (hydroxylase component of methane monooxygenase, in the background). Although quite a familiar feature in high‐valent manganese chemistry, the M₂(μ‐O)₂ diamond core motif has only recently been found in synthetic complexes for M=Cu or Fe. Despite differences in electronic structures that have been revealed through experimental and theoretical studies, Cu₂(μ‐O)₂ and Fe₂(μ‐O)₂ cores exhibit analogously covalent metal–oxo bonding, and similar tendencies to abstract hydrogen atoms from substrates. Our understanding of biocatalysis has been enhanced significantly through the isolation and comprehensive characterization of the Cu₂(μ‐O)₂ and Fe₂(μ‐O)₂ complexes. In particular, it has led to the development of new mechanistic notions about how non‐heme multimetal enzymes, such as, methane monooxygenase, fatty acid desaturase, and tyrosinase, may function in the activation of dioxygen to catalyze a diverse array of organic transformations. To find out more see the review by L. Que, Jr. and W. B. Tolman on p.1114 ff.     

Azole. 45.

The three title compounds, namely (Z)‐1‐(4,5‐di­nitro­imidazol‐1‐yl)‐3‐morpholinopropan‐2‐one 2,4‐di­nitro­phenyl­hydrazone, C₁₆H₁₇N₉O₉, (IV), (Z)‐3‐morpholino‐1‐(4‐morpholino‐5‐nitro­imidazol‐1‐yl)propan‐2‐one 2,4‐di­nitro­phenyl­hydrazone, C₂₀H₂₅N₉O₈, (Va), and (E)‐3‐morpholino‐1‐(4‐morpholino‐5‐nitro­imidazol‐1‐yl)propan‐2‐one 2,4‐di­nitro­phenylhydra­zone tetra­hydro­furan solvate, C₂₀H₂₅N₉O₈·C₄H₈O, (Vb), have been prepared and their structures determined. In (IV), the C‐4 nitro group is nearly perpendicular to the imidazole ring and the C‐4—NO₂ bond length is comparable to the value for a normal single Csp²—NO₂ bond. In (IV), (Va) and (Vb), the C‐­5 nitro group deviates insignificantly from the imidazole plane and the C‐5—NO₂ bond length is far shorter in all three compounds than C‐4—NO₂ in (IV). In consequence, the C‐4 nitro group in (IV) is easily replaced by morpholine, while the C‐5 nitro group in (IV), (Va) and (Vb) shows an extraordinary stability on treatment with the amine. The E configuration in (Vb) is stabilized by a three‐centre hydrogen bond.     

Anti-inflammatory drugs. X.

In the solid-state structure of the title compound, C₄H₁₀N⁺·C₁₄H₁₀Cl₂NO₂⁻·H₂O, the asymmetric unit contains one cation, one anion and a water mol­ecule. There is a network of hydrogen bonds which is similar to that found in the hydrated diethyl­ammonium diclofenac salt. A comparison is made of the molecular conformation of the anions in the two related structures.     

A new aromatic glucoside from stem bark of Illicium difengpi K.I.B. et K.I.M.

A new aromatic glucoside, namely 4-methoxyphenyl-(6-deoxy-α-L-mannopyranosyl)-β-D-glucopyranoside (1), together with six known aromatic glucosides (2–7) were isolated from the stem bark of Illicium difengpi. The structures of these compounds were established by spectroscopic methods. The isolated aromatic glucosides were tested for anti-inflammatory activity. Compounds 1, 3 and 6 showed significant inhibitory effect on nuclear factor kappa B (NF-κB) in RAW 264.7 macrophages induced by lipopolysaccharide.     

Trifluormethyl-schwefel-stickstoff-verbindungen. IX. Trifluormethansulfonamide

Trifluoromethanesulphonamide forms the following salts: CF₃SO₂NAg₂·NH₃, CF₃SO₂NAg₂, (CF₃SO₂NH)₂Hg and CF₃SO₂NH·NH₄. These salts are more reactive than the initial amide. CF₃SCl reacts with both silver salts to give the corresponding mono- and di-substituted derivatives, CF₃SO₂N(SCF₃)₂ and CF₃SO₂NHSCF₃, respectively. With phosgene and thiophosgene, CF₃SO₂NAg₂ reacts to give the pseudohalides CF₃SO₂NCO and CF₃SO₂NCS, respectively.     

E.S.R. and D.S.C. investigations of phase transitions in polymorphic 4-n-alkoxybenzylidene-4′-n-alkylanilines

Abstract

It is shown that the McMillan parameter M = T _SAN/T _N1 (where T _SAN and T _NI are respectively the temperatures of the smectic A to nematic (SAN) and the nematic to isotropic (NI) phase transitions) is useful in analysing the crossover between second and first order behaviour of the S_NN transition in the nO.m homologous liquid crystal series (the 4-n-alkoxybenzylidene-4′-n-alkylanilines). Using a phase diagram of orientational ordering versus M for this series, as obtained in this work (from E.S.R. and D.S.C), a symmetric tricritical point with mean field exponent β₂ = 1 is demonstrated. In a preliminary study of E.S.R. linewidth parameters B and C of nitroxide spin probes dissolved in members of the nO.m series exhibiting a first order S_AN transition, critical-type divergences are observed near this transition. In the case where M is closer to 0.959 (the value at the tricritical point), these divergences appear similar to those previously observed in related nO.m members with a second order S_AN transition; however, they are considerably enhanced for an M value closer to unity (i.e. more removed from the tricritical point). This indicates the importance of coupling between orientational and positional order parameters in the observed critical-type divergences.     

Structure investigations by P.A.C.

The perturbed angular correlation /P.A.C./ technique is employed to investigate the structures of barium ferrite and barium hexaferrite using radioactive¹³³Ba /10.7 Y/ as a probe. The quadrupole interaction frequencies /W_Q'S/ are found to be 9.68 and 12.02 Mrad sec^–1 for barium ferrite and barium hexaferrite, respectively, showing a drift from usual cubic structure.     

Stoffwechselprodukte von Mikroorganismen. 177. Mitteilung. Avilamycin C

From cultures of the Avilamycin (Avilamycin A) producing organism, Streptomyces viridochromogenes, strain ETH 23575, a second antibiotic, Avilamycin C, C₆₁H₉₀Cl₂O₃₂ could be isolated in crystalline form. Both Avilamycins belong to the group of the Orthosomycins. By IR., ¹H- and ¹³C-NMR. spectroscopy and by transformation to a common derivative it could be proven that Avilamycin A is a methyl ketone, Avilamycin C the corresponding methyl carbinol.     

Photochemische Reaktionen. 107. Mitteilung. Zur Photochemie offenkettiger 2,6-bzw. 2,7-Dien-Carbonylverbindungen

The Photochemistry of Open-Chained 2,6- or 2,7-Dien-Carbonyl Compounds On ¹n, π*-excitation (λ > 347 nm) citral (5) and the methyl ketone 10 isomerize to compounds A (7, 19) and B (6, 20) , whereas the phenyl ketone 11 changes into the isomer 24 of type E. Evidence is given that the conversions to A and B may arise from the ³n, π*-state of the 2,6-diene-carbonyl compounds. On ¹n, π*-excitation (λ = 254 nm) 5 and 10 yield the isomers A (7, 19) and D (18, 22) , but no products of type B. Furthermore, conversion of 10 to the isomer 21 of type C is observed. Selective ¹n, π*-excitation (λ = 254 nm) as well as selective ¹n, π*-excitation (λ > 347 nm) of the 2,7-diene-carbonyl compounds 12 and 13 give rise to isomerization to the compounds F (25, 28) , exclusively. The intramolecular [2 + 2]-photocycloadditions are shown to be triplet processes. UV.-irradiation (λ > 280 nm) of compounds F (25, 28) furnishes the isomeric products G (26, 29) which photoisomerize to oxetanes of type H (27, 30).     

Pseudochalkogenverbindungen. XXIV. Cyanamido-trimetaphosphimate

Pseudochalcogeno Compounds. XXIV. Cyanamido Trimetaphosphimates Synthesis and properties of sodium cyanamido trimetaphosphimates Na₃[P₃(NH)₃O_6?n(NCN)_n] (n:2,4) are reported. This compounds may be obtained by cautious hydrolysis of the corresponding hydrocyanamido-chloro-trimetaphosphimates, P₃N₃Cl_6?n(NHCN)_n. For sodium trimetaphosphimate, Na₃[P₃(NH)₃O₆] a simple, modified synthetic route is described. Possibilities of the formation of pseudochalcogeno-trimetaphosphimates of the type [P₃(NH) ₃O_6?n{C(CN)₂}_n]^3? (n = 2, 4) are discussed.     

Azinyl Sulfides. LXVII.

The title compound, C₆H₇NS, is planar, with endo‐C—N—C bond angles of 118.7 (2) and 118.8 (2)°, and C—S bond lengths of 1.697 (2) and 1.692 (2) Å for the two symmetrically independent mol­ecules. 1‐Methylpyridinium‐4‐thiol­ate is the major contributor to the molecular structure in the solid state.     

Triaziridine. 6. Mitteilung. Substituententransformationen an Triaziridinen

Substituent Transformations on Triaziridines Several novel triaziridines were prepared by substituent transformations starting from the known dialkyl-triaziridine-carboxylates 1a – c , with the aim to study the influence of the substitution pattern on the properties of the triaziridine ring. The dialkyl-triaziridines 2a – c were obtained by (t-BuO^?)-mediated demethylation and decarboxylation and the dialkyl-triaziridine-methanols 4a – c by LiAlH₄ reduction. Further reduction of the tosylates of 4a , b with LiAlH₄ gave the methyl-dialkyl-triaziridines 3a , b . The dialkyl-triaziridines 2a , c could not be N-methylated directly with CH₃I, but the anions 10a , c , obtained from 2a, c with CH₃Li, yielded 3a , c . N-Methylation of 2a with (CH₃)₃OBF₄ did not afford 3a but rather the methyl-triaziridinium salt 11 . The dialkyl-triaziridine 2c has pK_a > 14, its protonated species < 2. A concept that the electron pairs on the triaziridine N-atoms are more strongly localized than on amine N-atoms explains (a) that the dialkyl-triaziridine 2c is hardly basic, (b) that the LiAlH₄ reductions of the esters 1 stop at the stage of the methanols 4 , and (c) that the methanols 4a , b do not cleave like aminomethanols.     

Acetylenchemie. 9. Mitt. Anellierte imidazole aus N-propinylamid-vorstufen

The Compound 2-(N-Formyl-N-prop-2′-inyl)aminopyridine was cyclised in boiling formic acid to 3-methylimidazo[1,2-a]pyridine, with 3-methylene-2H-imidazo[1,2-a]pyridine as the intermediate. Under similar conditions the 1,3-diprop-2-inylpyrimido[4,5-b]quinoline-2,4-dione resulted from 1-methylimidazo[1,2-a]quinoline-4-carbonic acid-N-2-prop-2′-inylamide and from the 1-prop-2′-inylbenzo[b][1,8]naphthyridin-2-one the 1-methylbenzo[b]imidazo[1,2,3-ij]naphthyridine-4,7-dione as a new ring system, was obtained.