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2001 (1)
1Author    Gerhard Himbert, Oliver GerulatRequires cookie*
 Title    Einige Umsetzungen von Inhydrazinen mit Isocyanaten: [2+2]-und [4+2]Cycloadditionen, (Hydrazinoethinyl)metallierung Some Reactions of Ynehydrazines with Isocyanates: [2+2]-and [4+2]Cycloadditions, (Hydrazinoethynyl)metallation  
 Abstract    The (silylethynyl)-and the (tolylethinyl)-hydrazines la and lb react with aryl isocyanates 2 a -e and arylsulfonyl isocyanates 2f,g to form the corresponding substituted 3-arylimino-(or arylsulfonylimino-) l,l,2-trimethyl-5-oxopyrazolidinium-4-ides 3a-h. The silyl group in the 4-position can be replaced by a hydrogen atom (formation of 6a-e). Heating of 6d in toluene induced the unequivocal transformation of the betaine to an isomer, the spectrocopic data of which are in concordance with those of the 4-quinolone derivative 7. Aroyl isocyanates 8 react in a [4+2]cycloaddition with la to furnish the l,3-oxazin-4-ones 9a and b. The stannyla-ted ynehydrazine lc adds the cumulenic system of an aryl isocyanate (2d) across the Csp-Sn single bond, and trimethylstannyl ./V-(p-chlorophenyl)-3-(trimethylhydrazino)propiolimidate 10 is isolated. With two molecules of 2d the hydantoin derivative 11 is formed. 
  Reference    Z. Naturforsch. 56b, 1196—1204 (2001); eingegangen am 2. August 2001 
  Published    2001 
  Keywords    Cycloadditions, Cyclic Betaines, l, 3-Oxazin-4-ones 
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 TEI-XML for    default:Reihe_B/56/ZNB-2001-56b-1196.pdf 
 Identifier    ZNB-2001-56b-1196 
 Volume    56