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1994 (1)
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1978 (1)
1Author    Wolf-H GündelRequires cookie*
 Title    Reaktionen von Cyanpyridinium-Salzen mit Hydroxylamin Investigations of Quaternary Pyridinium Salts, XI [1] Reactions of Cyanopyridinium Salts with Hydroxylamine  
 Abstract    The preparation of quaternary pyridinium salts with amidoxime group in 2-, 3-and 4-position is described. The isomer with the substituent in 3-position rearranges on addition of base to a l-hydroxy-2-imino-3-pyridinecarbaldimine. The reaction of 3-cyano-pyridinium salts with hydroxylamine and potassium terf-butoxide gives derivatives of dipyrido[l,2-a: 3',4'-c]pyrrole. 
  Reference    Z. Naturforsch. 35b, 896—901 (1980); eingegangen am 21. März 1980 
  Published    1980 
  Keywords    Pyridinium Salts, Rearrangement, Condensation Reaction 
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 TEI-XML for    default:Reihe_B/35/ZNB-1980-35b-0896.pdf 
 Identifier    ZNB-1980-35b-0896 
 Volume    35 
2Author    El Sebai, A. Ibrahim, S. A. Shams, El Dine, FaridS G Soliman, IbrahimM. LaboutaRequires cookie*
 Title    Synthesis of 5,6-Diaryl-l,2,4-triazines  
 Abstract    The synthesis of 6-(4-methoxyphenyl)-5-phenyl-3-oxo-2,3-dihydro-I,2,4-triazine (5a) from 4-methoxybenzoin, 4-methoxybenzil, or 4-methoxybenzoin semicarbazone and semi-carbazide hydrochloride is reported. The condensation of 4-methoxybenzil with thiosemi-carbazide yielded 6-(4-methoxyphenyl)-5-phenyl-3-thioxo-2,3-dihydro-I,2,4-triazine (5b) which was converted to its 3-oxo analogue 5 a with acetic anhydride. Reduction of 5 a and 5 b with zinc and aqueous acetic acid led to the corresponding 2,3,4,5-tetrahydro-1,2,4-triazines 6 a and 6b, respectively. Oxidation of 5 b with iodine in sodium carbonate solution afforded bis [6-(4-methoxyphenyl)-5-phenyl-l,2,4-triazin-3-yl]disulphide (7). Analogous triazines were prepared by condensing 3,3'-diiodobenzil with semicarbazide hydrochloride or thiosemicarbazide. 
  Reference    Z. Naturforsch. 33b, 1503—1507 (1978); received July 24 1978 
  Published    1978 
  Keywords    4-Methoxybenzoin, 3, 3'-Diiodobenzil, Semicarbazide, Thiosemicarbazide, Condensation Reactions 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-1503.pdf 
 Identifier    ZNB-1978-33b-1503 
 Volume    33 
3Author    Stefan Horstmann, Wolfgang SchnickRequires cookie*
 Title    Synthese, Kristallstruktur und Eigenschaften von Tetraaminophosphoniumiodid [P(NH2)4]I Synthesis, Crystal Structure, and Properties of Tetraaminophosphonium Iodide [P(NH2)4]I  
 Abstract    The title compound has been prepared starting from phosphorothionic triamide SP(N H 2)3 by methylation of the sulfur atom and subsequent ammonolysis reaction in dry acetonitrile and dichloromethane, respectively, both at room temperature. Suitable single crystals are obtained from an acetonitrile solution in a temperature gradient between 70 °C and room temperature. The crystal structure o f [P(N H 2)4]I has been determined by single crystal X-ray methods (P 4!nbm\ a = 842.6(2), c = 486.7(2) pm, Z = 2). In the solid [P(NH2)4]+-and I~-ions are found with significant N -H -I -h y d r o g e n bonding interactions between anions and cations (H —I: 276.4 pm). The P -N -b o n d length in the cation (160.7(2) pm) represents the shortest P -N H 2 bond distance reported to date indicating a significant electrostatic strengthening. The condensation behaviour of [P(N H 2)4]I in solution and in the solid has been investigated. 
  Reference    Z. Naturforsch. 49b, 1381—1386 (1994); eingegangen am 5. Mai 1994 
  Published    1994 
  Keywords    Tetraaminophosphonium Salt, Synthesis, Crystal Structure, Hydrogen Bonding, Condensation Reactions 
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 TEI-XML for    default:Reihe_B/49/ZNB-1994-49b-1381.pdf 
 Identifier    ZNB-1994-49b-1381 
 Volume    49