ISSN:
0009-2940
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Synthesis of 4,6,7,9-Tetramethoxy-3,10-perylenequinoneUllmann's reaction of 2-iodo-3,5-dimethoxybenzaldehyde (1 c) yields 4.4′.6.6-tetramethoxy-biphenyl-2,2,-dialdehyde (2), a favourite starting material for facile preparation of 2,4,5,7-tetra-methoxy-9,10-phenanthrenequinone (4). This compound reacts with triallylborane to form trans-9,10-diallyl-2,4,5,7-tetramethoxy-9,10-dihydro-9,10-phenanthrendiol (6a). from which the dilactone 6e can be prepared by reaction with diborane followed by oxidation of the tetrahydroxy compound 6c. Zinc dust interaction of diethyl trans-9,10-dichloro-2,4,5,7-tetramethoxy-9,10-dihydro-9,10-phenanthrenedipropionate (6f) leads to the dicarboxylic acid 7b. Reaction of 7b with polyphosphoric acid gives 4,6,7,9-tetramethoxy-1,12-dihydroperylene-3(2H),10(l1H)-dione (8), which is dehydrogenized to 4,6,7,9-tetramethoxy-3,10-perylenequinone (9)
Notes:
Durch Ullmann-Reaktion des 2-Iod-3.5-dimethoxybenzaldehyds (l c) entsteht der 4,4′,6,6′-Tetramethoxybiphenyl-2,2,-dialdehyd (2), der leicht in das 2,4,5,7-Tetramethoxy-9,10-phenanthren-chinon (4) übergeführt werden kann. Durch Behandlung mit Triallylboran entsteht das trans-9,10-Diallyl-2,4,5,7-tetramethoxy-9,10-dihydro-9,10-phenanthrendiol (6a), das nach Hydroborierung und Oxidation der Tetrahydroxyverbindung 6c in das Dilacton 6e übergeht. Durch Zinkstaubeinwirkung auf den trans-9,10-Dichlor-2,4,5,7-tetramethoxy-9,10-dihydro-9,10-phenanthren-dipropionsäure-diethyiester (6f) bildet sich die Dicarbonsäure 7b, die durch Polyphosphorsäure zum 4,6,7,9-Tetramethoxy-1,12-dihydroperylen-3(2H). 10(11H)-dion (8) führt. das leicht zum 4,6,7,9-Tetramethoxy-3,10-perylenchinon (9) dehydrierbar ist.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19791120735
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