22859-64-9Relevant academic research and scientific papers
Synthesis and Reactions of Some Pyridoquinolines (1,8-Diazaanthracenes)
Quast, Helmut,Schoen, Norbert
, p. 133 - 146 (2007/10/02)
The pyridoquinolines 1b, c, and e are synthesized for the first time directly by Friedlaender condensation from 4,6-diaminoisophthalic aldehyde (6) and ketones.Copper(I)-catalyzed decarboxylation of the 2,8-dicarboxylic acid 1e occurs in diethylene glycol monoethyl ether at temperatures as low as 165 deg C affording the parent compound 1a in high yield.Despite steric hindrance by a tert-butyl group methyllithium adds to position 2 of the 2,8-di-tert-butyl compound 1c producing the 1,2-dihydropyridoquinoline 9.Dehydrogenation of the octahydroquinoacridine 7 using palladium on carbon at 250 deg C yields the 1,2,3,4,7,12-hexahydro- (10) and the 5,14-dihydroquinoacridine (11).
