Synthesis, NMR, IR spectroscopic and X-ray study of novel [pyridazin-3(2H)-one-6-yl]ferrocenes and related ferrocenophane derivatives. Study on ferrocenes. Part 14

On treatment with glyoxylic acid and hydrazine hydrate, 1,1′-diacetylferrocene was converted into the separable mixture of 1,1′-bis [pyridazin-3(2H)-one-6-yl]ferrocene and the hydrazone as well as the azine of 1-acetyl-1′-[pyridazin-3(2H)-one-6-yl]ferrocene. Successful cyclizations of 1,1′-bis[pyridazin-3(2H)-one-6-yl]ferrocene resulting in a series of novel ferrocenophanes containing heterocyclic units were performed under phase transfer- and homogeneous catalytic (RCM) conditions by the application of versatile dialkylating agents and second generation Grubbs’ catalyst, respectively. The structures were determined by mass spectrometry, IR, 1H and 13C NMR spectroscopy including 2D-COSY, HMQC and HMBC measurements. The solid phase structure of a dimer product with π-stacking interaction was revealed by X-ray analysis.