246-92-4Relevant articles and documents
Formation of cyclopent[a]indene and acenaphthylene from allyl esters of biphenyl mono- and di-carboxylic acids and from biphenyl dicarboxylic anhydrides on flash vacuum pyrolysis at 1000-1100°C
Bapat, Jayant B.,Brown, Roger F.C.,Bulmer, Glenn H.,Childs, Trevor,Coulston, Karen J.,Eastwood, Frank W.,Taylor, Dennis K.
, p. 1159 - 1182 (2007/10/03)
Flash vacuum pyrolysis at 1000-1100°C of the allyl esters of the three isomeric biphenylcarboxylic acids, of the allyl esters of the 12 biphenyldicarboxylic acids and of the three biphenyldicarboxylic anhydrides gave pyrolysates which were examined by 1H n.m.r. spectroscopy at temperatures below -50°C. In all cases the spectra showed the presence of cyclopent[a]indene and acenaphthylene together with other products. Possible mechanisms for these ring contraction and cyclization processes are discussed and the results of pyrolyses of [2,3-13C2]biphenyl-2,3-dicarboxylic anhydride, and [3,4-13C2]-and (2-2H1)-biphenyl-3,4-dicarboxylic anhydrides are reported.
Cyclopentindene (Benzopentalene): Generation by Flash Vacuum Pyrolysis and Subsequent Dimerisation
Brown, Roger F. C.,Choi, Neil,Coulston, Karen J.,Eastwood, Frank W.,Wiersum, Ulfert E.,Jenneskens, Leonardus W.
, p. 4405 - 4408 (2007/10/02)
Cyclopentindene (benzopentalene, 7) is generated by flash vacuum pyrolysis of 3-phenylphthalic anhydride (6), biphenylene (3) or diphenic anhydride (4).It dimerises readily and adds cyclopentadiene above -70 deg C, but it does not equilibrate at 900 deg C with as-indacene (1).
