Zur Aminolyse von Bis-Imidoylchloriden der Oxals�ure II. Umsetzung mit Diaminen und Aminoalkoholen

Abstract

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.

Regioselective Anionic [3+2] Cyclizations of Isoxazole, Pyrazole and 1,2,4-Triazole Dinucleophiles − Efficient Synthesis of 2,4-Dihydroimidazo[4,5-b]quinoxalines, 3H-Imidazo[1,2-b]pyrazoles and 5H-Imidazo[2,1-c][1,2,4]triazoles

“…Ϫ The oxaldiimidoyl dichlorides 2 were prepared according to literature procedures. [7] Ϫ For 1 H NMR and 13 C NMR spectra, the deuterated solvents indicated were used. Ϫ Mass spectrometric (MS) data were obtained using the electron ionization (70 eV) or the chemical ionization techniques (CI, H 2 O).…”

“…[7] These reactions afforded a variety of structurally interesting and biologically relevant benzimidazoles and diazabicyclo[2.2.1]heptanones. We have also studied cyclizations of oxaldiimidoyl dichlorides with 3-aminopyrazoles, 3-amino-1,2,4-triazoles and 3-aminoisoxazoles.…”

Efficient Synthesis of Nitrogen Heterocycles by Cyclization of Bis(nucleophiles) with Oxaldiimidoyl Dichlorides

“…[29] Because of the rigid character of 79, formation of a 1:1 cyclization product was sterically not possible. …”

“…[29] This compound might be useful for the simultaneous complexation of transition and alkali metal ions. Scheme 22.…”

Komplexbildung und selektive Cyclisierung substituierter Oxalamidine

“…Mit Dianionen werden häufig unter nucleophilem 1,2-Angriff am Imidoylchlorid Heterocyclen mit Oxalamidin-Substruktur erhalten [3]. Die Synthese der offenkettigen Oxalamidine (Typ 1) erfolgt unter Retention der Hybridisierung der Stickstoffatome [2, 4].…”