13C-NMR.-Spektren von Dicyanhydrochinonen und Dicyan-p-benzochinonen

¹³C-NMR. Spectra of Dicyanohydroquinones and Dicyano-p-benzoquinones The ¹³C-NMR. spectra of 12 dicyanohydroquinones and fully substituted dicyano- and diazido-p-benzoquinones have been measured and assigned by comparison with related benzene and p-benzoquinone derivatives. For p-benzoquinones the influence of the cyano and azido substituents on the chemical shift of the CO-, α- and β-C-atoms has been investigated.     

Über die Synthese von 1-Aryl-und 1-Alkyl-2, 3-dimethyl-chinoxalinium-perchloraten. 2. Mitteilung. Synthese und 1H-NMR.-Spektren von 2,3-Dimethyl-1-phenyl-6-X-chinoxalinium-perchloraten

On the Synthesis of 1-Aryl- and-1-Alkyl-2, 3-dimethyl-quinoxalinium Perchlorates. 2nd Communication

1 1. Mitt.: [1].

. Synthesis and ¹ H-NMR. Spectra of 2, 3-Dimethyl-1-phenyl-6-X-quinoxlinium Perchlorates The synthesis of the title compounds ( 5 ) which have been useful as precursors for a lot of conventional and new-type dyes [2-8] has yet been limited to examples with X?H [2] [3] [11] [15] and with electron-donating [4] [12] or at best slightly electron-accepting [1] [6] substituents X and R. We now describe a method suitable even for compounds 5 with strongly electron-accepting substituents: N-monosubstituted o-phenylendiamines 4 , were condensed with 2, 3-butanedione and perchloric acid in mixed solvents containing an excess of diethyl ether. The products - mostly substituted at position 6 of the quinoxalinium ring - are chracterized by ¹H-NMR. spectra, elemental analyses and in most cases by isolation of the corresponding bases 6 . Correlations of chemical shifts with Hammett's σ_p [18] are given by equations (1)-(5).     

Synthese und Strukturaufklärung von Merucathinon und Synthese von Cathinon. Inhaltsstoffe von Catha edulis FORSK

Synthesis and Structure Elucidation of Merucathinone and Synthesis of Cathinone. Constituents of Catha edulis FORSK . Starting from L-alanine, two constituents of Catha edulis FORSK ., (S)-4-amino-1-phenylpent-1-en-3-on ((S)- 3 ; merucathinone) and (S)-2-amino-1-phenylpropan-1-on ((S)- 1 ; cathinone) were synthesized.     

Synthese von Betenamin und von Betalain-Modellsubstanzen

Synthesis of Betenamine and of Betalaine Model Substances For comparisons of color, spectroscopic properties, pK_a values, and stabilities, a number of model substances containing the 1,7-diazaheptamethinium chromophore 8 of the yellow and red betalaine plant pigments were prepared by the thermal or photolytic ring opening of simple pyridine derivatives (such as 2 and 14-16 ), followed by the introduction of amines. Among the novel compounds prepared were betenamine perchlorate ( 5 ), the ‘naked’ ring system of the beet-pigment betanine ( C ) as well as two 1,7-diazaheptamethinium salts 25 and 27 with terminal amono acids. The synthesis of 5 started with 4-(2-aminoethyl)pyridine ( 1 ) and proceeded via 2 , ring opening with indoline to 4 , saponification, and intramolecular amine replacement (Scheme 1). The syntheses of 25 and 27 involved only one step, namely ring opening of γ-picoline using (S)-cyclodopa ( 24 ) and (S)-proline ( 26 ), respectively (Scheme 3).     

Synthese und Charakterisierung von Natriumcyanamid

Synthesis and Characterization of Sodium Cyanamide The synthesis of Na₂CN₂ was carried out by reaction of sodium amide with sodium hydrogen cyanamide at 200 °C, in vacuum. Single crystals were obtained while heating the product (500 °C, 8 days) in silver crucibles. The title compound was characterised by single crystal X‐ray diffraction and IR‐spectroscopy (C2/m; Z = 2, a = 5.0456(3), b = 5.0010(3), c = 5.5359(3) Å; β = 110.078(5)°; R1 = 3.18%, wR2 = 6.35%, GOF = 1.078). The CN₂^2– units are linear exhibiting a C–N bond length of 1.236(1) Å, while sodium is coordinated by five nitrogen atoms forming a square pyramid. The structural relationships to aristotypic Na₂HgO₂ are pointed out.     

Synthese und Charakterisierung von Dimesitylzink

Synthesis and characterization of dimesityl zinc Dimesityl magnesium reacts with zinc chloride in THF solution forming dimesityl zinc. This compound is free of solvent and monomer in benzene. 2,2′-Bipyridine and tetramethylethylenediamine yield weak complexes. Thermal behaviour and spectroscopic properties of these compounds and some reactions of ZnMes₂ are described.     

Synthese und eigenschaften von dialkylaminodifluorarsinen

The reactions of secondary amines with AsF₃ lead to the formation of dialkylaminodifluorarsines F₂As-NR₂. Eight aminoarsines have been prepared by this method and are describe. IR, ₁₉F and ₁H-NMR and mas spectral data are presented for these compounds and discussed. The fluorination of aminodicholorarsines Cl₂As-Nr₂ with SbF₃ or ZnF₂ produces only small yields of the difluorarsines F₂As-NR₂; fluorination of AsCl₃ under the same conditions, however, is a suitable preparative method for the synthesis of AsF₃.     

Synthese und Charakterisierung von Quecksilbercyanamid

Synthesis and Characterisation of Mercury Cyanamide HgCN₂ was prepared by double conversion of HgCl₂ with sodium cyanamide in aqueous solution. Its crystal structure has been determined using X‐ray powder data and refined by combined profile fits using X‐ray and neutron diffraction data (Pbca, Z = 8, a = 10.4851(1), b = 6.5138(1), c = 6.8929(1) Å; R_p (X‐ray) = 6.15%; R_p (neutrons) = 2.33; 2.43%). The cyanamide‐anion is bent (172.4(7)°), which has been confirmed by vibrational spectroscopy. Mercury and carbon form zigzag chains. Not including nitrogen, the structure is related to the MnP‐structure type.