M. Biedermann

On the Ambident Behaviour of Dicyanmethanidonitrite; Syntheses and Characterization of Complexes of the Type [M{N(O)C(CN)2}(PPh3)n] (M = CuI, AgI; n = 2, 3)

Complexes of the type [M{N(O)C(CN)2}(PPh3)n] (M = CuI, AgI, n = 2, 3) were synthesized by metathesis of K[N(O)C(CN)2] and [M(NO3)(PPh3)n]. The complexes were characterized by 13C-, 31P-NMR and IR spectroscopy and elemental analyses. The crystal structures of [M{N(O)C(CN)2}(PPh3)2]2 (M = CuI, AgI) have been determined by X-ray diffraction. Depending on the metal atom in the complexes [M{N(O)C(CN)2}(PPh3)3] the ionic ligand is coordinated via the central nitrogen (copper) or the oxygen atom (silver). In addition the two copper and silver complexes [M{N(O)C(CN)2}(PPh3)2]2 are not isostructural but have quite different structures. For M = Cu the two copper atoms are doubly bridged by two NCCN sequences, forming an approximately planar Cu(NCCN)2Cu ring. On the other hand, in the homologous silver derivative the metal atoms are also doubly bridged, but by two NO groups, thus forming a planar six-membered ring.

A Facile Synthesis of Substituted 1,4-Benzothiazepin-5(4H)-ones and Pyrido[3,2-f][1,4]thiazepin-5(4H)-ones − Crystal and Molecular Structure of 2-Ethylthio-4-methyl-5(4H)-oxopyrido[3,2-f][1,4]thiazepine-3-carbonitrile

A new synthesis of pyrido[3,2-f][1,4]thiazepine derivatives 3 starting with 2-chloronicotinic acid (1), methylaminoacetonitrile hydrochloride and carbon disulfide is described. As proved by a crystal structure determination, a boat conformation with approximated mirror symmetry can be assigned to the 1,4-thiazepine ring in 3b. 2-Chloro-N-cyanomethyl-N-methyl-5-nitrobenzamide (5) reacts with carbon disulfide in presence of a strong base in DMF or DMSO depending on the temperature to either the benzothiopyran compound 6 or by intramolecular aromatic nucleophilic substitution to a seven-membered ring system as thiolate anion which can be alkylated to give the 1,4-benzothiazepine derivative 7, or to an open-chain amido ketene dithioacetal 8.

Pseudoelementverbindungen IX. Organostannylierung von Cyanamidonitrat — Molekül- und Kristallstruktur von N-Trimethylstannyl-N′-nitro-carbodiimid

Abstract Considered under the aspect of its ambidence, the reactivity of cyanamidonitrate [NO2NCN]− towards triorganostannyl chlorides was investigated. The reaction products of type R3Sn-NCN-NO2 were characterized by 1H-NMR, 13C-NMR, 119Sn-NMR and IR spectroscopy. While cyanamides of the type [RnE(Y)NCN]− (RnE(Y) = RC(O), RC(NCN), R2 P(O), R2P(S), R2P(NCN), RSO2) are coordinated exclusively either via the terminal nitrogen (monodentately) or via both the nitrile group end on and the chalcogen atom (bidentately), we found N-triorganostannyl-N′-nitro-carbodiimides as the first example in which the NCN group acts as a bidentate bridge with metal-N bonds in 1- and 3-position. For Me3Sn-NCN-NO2 the crystal structure was determined.

Enantiomere und diastereomere 2-Methoxymethyl-pyrrolidin-1-dithiocarbonsäureester

SummaryFormation of the 2-methoxymethyl-pyrrolidine-1-dithiocarboxylates2–4 and alkylation of2 and3 were studied. Enantiomeric and diastereomeric derivatives of4, the preparation of diastereomeric mixtures of4 by alkylation of3 in the presence of strong bases, and formation of6 by phase transfer alkylation of2 are described. The two enantiomers of 2-(4-bromophenyl)-2-oxo-ethyl 2-methoxymethylpyrrolidine-1-dithiocarboxylate2 have been characterized by X-ray analysis.

Koordinationsambidenz des Thiocyanations in Alkalitrithiocyanatomanganat(II)-Hydraten / Coordination Ambidence of the Thiocyanate Anion in Alkali Trithiocyanatomanganate(II) Hydrates

Abstract Alkali metal trithiocyanatomanganate(II) hydrates have been prepared and characterized by several analytical methods. The structures of NH4[Mn(NCS)3(H2O)] (1a), K [Mn(NCS)3(H2O)] (1b) and Na[Mn(NCS)3] · 3 H2O (2) could be elucidated by X-ray analysis, 1a and 1b are isotypic and form a polymeric layer structure which is characterized by the ambident nature of the thiocyanate ligand and binding of the water molecule to the octahedrally coordinated Mn atom. In 2 the complex manganate(II) anions form a layer structure with trigonal symmetry in which each Mn atom is connected with three Mn neighbours by thiocyanate double bridges. The cation partial lattice consists of infinite chains of face-sharing [Na(H2O)6]+ octahedra running perpendicular to the anion layers.

DITHIOCARBOXYLIERUNGSREAKTIONEN VON cis-BICYCLO[3.3.0]OCTAN-3,7-DIONEN. MOLEKÜL- UND KRISTALLSTRUKTUR VON cis-2,6-BIS(DIMETHYLTHIO-METHYLEN)-BICYCLO[3.3.0]OCTAN-3,7-DION

Abstract The cis-bicyclo[3.3.0]octane-3,7-dione 1a and its 1,5-dimethyl derivative 1b react with carbon disulfide, strong base and an alkylating agent in dipolar aprotic solvents giving racemic mixtures of 2-dialkylthio-methylene compounds 2, whereas in the presence of two equivalents of carbon disulfide and the appropriate amount of base and further alkylating agent the cis-2,6-bis(dimethylthio-methylene) derivatives 3 are formed. The crystal and molecular structure of 3a has been investigated by X-ray analysis.

ARYL THIOCARBAMOYLATIONS OF PHTHALIDES AND X-RAY STUDIES OF THREE REACTION PRODUCTS

Abstract Phthalides 1 have been thiocarbamoylated. We were able to isolate and characterize different reaction products formed by treatment of a mixture of 1 and phenyl isothiocyanate with various amounts of base. 3-Oxo-1,3-dihydro-isobenzofuran-1-carbothioic acid phenylamide 3, 3-{[(1-oxo-3H-isobenzofuranylidene)-phenylamino-methylenethio]methylthio-phenylamino-methylene}-3H-isobenzofuran-1-one 4, 3-oxo-N,1-diphenyl-1,3-dihydro-isobenzofuran-1-carboximidothioic acid methyl ester 5, 3-alkylthio-4-hydroxy-2-phenyl-2H-isoquinolin-1-one 6, and 3-oxo-N,N-diphenyl-3H-isobenzofuran-1,1-dicarboximidothioic acid dimethyl ester 7 were obtained. X-ray studies have been performed in order to identify unequivocally the reaction products.

Crystal structure of N2, N2-dimethylacetamidinium N, N-dimethylcarbamate

The title compound crystallizes in the monoclinic space group P2 1 /c with four formula units in a unit cell of dimensions a = 10.814(2), b = 8.400(2), c = 11.398(4) A, β = 110.86(2)°, V = 967.5(5) A 3 . The crystal structure is characterized by almost exactly planar [Me 2 NC(NH 2 )Me] + cations and [O 2 CNMe 2 ] anions which are approximately perpendicular oriented to one another. The amidine N 1 -C and N 2 -C bond lengths are significantly different (1.341(7) and 1.292(7) A, respectively) but the C-O distances of the carbamate anion are equal within experimental error (1.263(6) and 1.256(6) A). An essential feature of the crystal structure are N-H…O hydrogen bonds between cations and anions.

Reaktionen von 2-Methyl-1H-benzimidazol mit Schwefelkohlenstoff und Phenylisothiocyanat. Kristall- und Molekülstruktur von 1,1′ -Carbonothioyl-bis(2-methyl-1H-benzimidazol) und 2-Methyl-1-(ethoxycarbonylmethylthio-phenylimino)-1H-benzimidazol / Reactions of 2-Methyl-1 H-benzimidazole with Carbon Disulfide and Phenyl Isothiocyanate. Molecular and Crystal Structures of 1,1′-Carbonothioyl-bis(2-methyl-1 H-benzimidazole) and 2-Methyl-1-(ethoxycarbonylmethylthio-phenylimino)-1 H-benzimidazole

Abstract 2-Methyl-1 H-benzimidazole 1 reacts in the presence of two equivalents of sodium hydride in dry DMSO with carbon disulfide to methyl 2-methylbenzimidazole-1-dithiocarboxylate 3 using methyl iodide as alkylating agent, whereas using 1,2-dibromoethane 1,1′-carbonothioyl bis(2-methyl-1 H-benzimidazole) 5 is formed. Compound 1 reacts with phenyl isothiocyanate in the presence of one equivalent of sodium hydride in dry DMF after alkylation to 2-methyl-1-( alkylthio-phenylimino)-1 H-benzimidazoles 6a, 6b. Reaction products 5 and 6b have been identified and structurally characterized by X-ray analysis.