The reactions of aryllithium compounds with 2-arylquinolines

In the reaction of p-tolylquinoline with phenyllithium, an insoluble (in ether), high melting point yellow compound was found in addition to the major product 2-phenyl-2-(p-tolyl)-1,2-dihydroquinoline. The compound, named "yellow compound Y" was identified as 6,15-dimethyl-tribenzo- (c,f,j) -naphtho- (1,2,3,4) - (i,m,n) - (2,7) -phenathrolene (Fig. 8-11). The reactions of aryllithium compounds with other 2-aryl-quinolines were performed in the attempt to synthesize a series of compounds which are analogous to the "yellow compound Y," and to gain more insight about the reactions. Attempts to make a series of "yellow compounds" have not yet been successful; but, the isolation and identification of some intermediates and products, such as the carboxylic acid of 2-m-tolylquinoline (Fig. 35), and the "dimer" (Fig. 25) of 2-phenyl-8-methylquinoline, have given us some valuable information and clues about the reaction mechanisms, and the formation of the "yellow compounds." Further investigations are needed for more understanding of the reaction mechanism and the formation of the "yellow compound.".