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Es werden neue Synthesen fur Quadratsaure-1,2- und -1,3-diamide beschrieben. Diamide aus prim. Aminen sind an beiden Stickstoffatomen alkylierbar. 1,2-Diamide aus sek. Aminen werden in Dithio-diamide ubergefuhrt, die sich an den beiden Schwefelatomen zu den Cyclobutadien-Dikationen 72 und 73 methylieren lassen. Das aus o-Phenylendiamin entstandene 1,2-Diamid 26 ist glatt zu Cyclobuta[b]chinoxalin-1,2-dion (76) oxidierbar, dessen Vierring protolytisch geoffnet werden kann. Das 1,2- und 1,3-Diamid 40 und 50 sind zu den Radikalkationen 82 bzw. 83 oxidierbar. Amides and Thioamides of Squaric Acid: Syntheses and Reactions New syntheses are reported for squaric acid 1,2- and 1,3-diamides. Diamides derived from primary amines can be alkylated at the nitrogen atoms. 1,2-Diamides from secondary amines are transformed into dithio-diamides which on methylation of both sulfur atoms form the cyclobutadiene dications 72 and 73. The 1,2-diamide 26, derived from o-phenylenediamine, is smoothly oxidized to cyclobuta[b]quinoxaline-1,2-dione (76) in which the four-membered ring can be opened by protolysis. The 1,2- and 1,3-diamides 40 and 50 are oxidized to the radical cations 82 and 83, respectively. |
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