Zur Aminolyse von Bis-Imidoylchloriden der Oxalsäure II. Umsetzung mit Diaminen und Aminoalkoholen

On the Aminolysis of Bis-Imidoylchlorides of Oxalic Acid. II. Reaction with Aliphatic Diamines and Aminoalcohols The aminolysis of bis-imidoylchloride 1 derived from oxalic acid with several diamines and aminoalcohols was investigated. At room temperature diamines 2 as well as aminoalcohols 7 give mainly the cyclic amidines 3 and mixed amidine-imidates 8 in moderately up to good yields. While cis-1,2-diaminocyclohexane yields at room temperature the bicyclic amidine 3a , the trans isomer reacts to 3b only when heated for several hours. Depending on the conditions, the racemic 1,2-diaminopropane 2h gives derivatives of pyrazine 3h or the open-chain amidine 5 resulting from an oxidative aromatization and subsequent hydrolysis. Histamine 2i and 1,8-diamino-3,6-dioxaoctane 2p react selectively with 1 to seven- respectively twelve-membered heterocycles 3i and 3p. The mixed aliphatic and aromatic diamines 2n, o show an anomalous behaviour leading to 2,2′-bis-chinazolines 3n, o . In comparison with acyclic oxalic amidines the new cyclic derivatives show less molecular dynamic in their nmr spectra. In some cases, a s-trans-arrangement of the amidine substructure was observed.