| タイトル | Synthesis of asymmetric tetracarboxylic acids and corresponding dianhydrides |
| 本文（外部サイト） | http://hdl.handle.net/2060/20090006604 |
| 著者（英） | Chuang, Chun-Hua |
| 著者所属（英） | NASA Headquarters |
| 発行日 | 2008-09-16 |
| 言語 | eng |
| 内容記述 | This invention relates to processes for preparing asymmetrical biphenyl tetracarboxylic acids and the corresponding asymmetrical dianhydrides, namely 2,3,3',4'-biphenyl dianhydride (a-BPDA), 2,3,3',4'-benzophenone dianhydride (a-BTDA) and 3,4'-methylenediphthalic anhydride (-MDPA). By cross-coupling reactions of reactive metal substituted o-xylenes or by cross-coupling o-xylene derivatives in the presence of catalysts, this invention specifically produces asymmetrical biphenyl intermediates that are subsequently oxidized or hydrolyzed and oxidized to provide asymmetric biphenyl tetracarboxylic acids in comparatively high yields. These asymmetrical biphenyl tetracarboxylic acids are subsequently converted to the corresponding asymmetrical dianhydrides without contamination by symmetrical biphenyl dianhydrides. |
| NASA分類 | Chemistry and Materials (General) |
| 権利 | No Copyright |
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