The main aim of this project was to optimize the conversion of 2,2', 4,4', 6,6' - hexanitrobibenzal (DPE) into 2,2', 4,4',6,6' - hexanitrostilbene (HNS). This was acheived in that conversions of greater than 90% were obtained when using salts of carboxylic acids as bases and oxygen as oxidant in dymethylsulphoxide solution. During the course of the work, studies of n.m.r spectra, reaction kinetics and electrochemistry provided convincing evidence that reaction proceeds via oxidation of the DPE monoanion which is in equilibrium with the more stable dianion and the substrate. It was also found possible to produce the DPE dianion by electrolytic reduction of HNS. In order to obtain more general information pertaining to the dehydrogenation of compounds of this type, a number of variously nitrosubstituted bibenzyls including naphthalene analogues, were prepared and their base induced dehydrogenations, in the presence of oxygen, studied. In general it was found that the substitution of nitro groups in ortho positions was disadvantageous except in the case of DPE itself. P,P' - Dinitrobibenzyl and 1,2-di-(4-nitro-1-naphthyl)ethane were found to be readily prepared and dehydrogenated in good yield using t-butoxide anion in dimethylsulphoxide solution under oxygen. In the former case, kinetic evidence was obtained which suggests that reaction proceeds via the dianion in contrast to the DPE.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:354370 |
| Date | January 1985 |
| Creators | Jayaweera-Bandara, A. M. |
| Publisher | Kingston University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://eprints.kingston.ac.uk/20500/ |
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