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, H-1 and C-13 NMR spectroscopy including 2D-COSY, HMQC and HMBC measurements. The solid phase structure of a dimer product with pi-stacking interaction was revealed by X-ray analysis. (C) 2004 Elsevier B.V. All rights reserved.