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Methyl-methine linkages of Novolac, a commercially available t-butylphenol acetylene condensed (TBPA) resin, have been identified by recognition of pyrolysis pathways using pyrolysis-gas chromatography/mass spectrometry (Py-GC/mS) in vulcanized rubber. The diagnostic mass spectrum of t-butylphenol with methyl-methine linkages between phenolic rings was observed at m/z 192, corresponding to 4-t-butyl-2-ethyl-6-methylphenol. Other molecular ions were observed at m/z 178, 164, and 150 in the characteristic pyrolyzates. The ion at m/z 192 in the TBPA resin was observed to be characteristic for methyl-methine linkages between the phenolic groups, and the analytical pyrolysis-GC/mS method was thus able to identify the resin at low levels in vulcanized rubber. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
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Guzzo PR Buckle RN Chou M Dinn SR Flaugh ME Kiefer AD Ryter KT Sampognaro AJ Tregay SW Xu YC 《The Journal of organic chemistry》2003,68(3):770-778
Methodology to prepare 8-amido-2-amino-1,2,3,4-tetrahydro-2-dibenzofurans, analogues with a fluorine substituent incorporated in the 6-, 7-, and 9-positions, and a difluorinated analogue with fluorines in the 6- and 9-positions is described. The tetrahydrodibenzofuran ring systems are prepared by acid-catalyzed [3,3]-sigmatropic rearrangement of O-aryloximes. Regioselective reactions to prepare the requisite O-aryloxime intermediates from commercially available fluorobenzene derivatives are discussed. 相似文献
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