81330-16-7Relevant academic research and scientific papers
SYNTHESIS OF 1,6-DIAZABIPHENYLENE BY FLASH VACUUM PYROLYSIS OF 2,5,9,10-TETRA-AZAPHENANTHRENE; NMR EVIDENCE FOR REHYBRIDISATION IN BIPHENYLENES.
MacBride, J. A. Hugh,Wright, Peter M.,Wakefield, Basil J.
, p. 4545 - 4548 (1981)
A mixed Ullmann reaction between 2- and 4-chloro-3-nitropyridines furnished 3,3'-dinitro-2,4'-bipyridyl and reduction to 2,5,9,10-tetra-azaphenanthrene followed by thermal extrusion of nitrogen gave 1,6-diazabiphenylene; different complexing abilities of the two nitrogen atoms of this compound were revealed by 1H nmr using Eu(fod)3 which are consistent withprevious work on the rehybridisation in strained ring systems and the value of 1JC-H in biphenylene.
BIPHENYLENES AND HETEROCYCLIC ANALOGUES OF BIPHENYLENE. PART IV. ELECTROPHILIC AND NUCLEOPHILIC REACTIONS AND BASICITIES OF 1,6-, 1,8-, AND 2,7-DIAZABIPHENYLENES.
MacBride, J. A. Hugh,Wright, Peter M.
, p. 3001 - 3018 (2007/10/02)
The basicities of three diazabiphenylenes (DABPs) and the relative complexing ability of the nitrogen atoms of 1,6-DABP correspond with the postulated increase in effective electronegativity of the ring-junction carbon atoms associated with re-hybridisation.The mono-N-oxide of 2,7-DABP is obtained using m-chloroperbenzoic acid and gives 3-chloro-2,7-DABP with phosphoryl chloride; the structures of these compounds are confirmed by formation of O- and N-methyl iodides respectively.Thiophosgene and base opens one pyridine ring of 2,7-DABP while sodium hydroxide opens the 4-membered ring of each of the three DABPs giving pyridyl-pyridones. 2,7-DABP forms a putative N-nitro-derivative with nitronium tetrafluoroborate and a 1:1 adduct with o-phenylene di-isothiocyanate.A mixed Ullmann reaction between 2-chloro- and 4-chloro-3-nitropyridines gives a minor amount of 3,3'-dinitro-2,4'-bipyridyl which furnishes 1,6-DABP after reductive cyclisation and flash vacuum pyrolytic extrusion of dinitrogen.
