Carcinogenic nitrogen compounds. Part LXXIX. A route to new condensed acridines containing a cyclopent[kl]acridine nucleus

The reaction of 7-o-chlorophenylbenz[c]acridine with sodium hydroxide in benzo[h]quinoline affords a mixture of 7-phenylbenz[c]acridine, benz[c]indeno[1,3-kl]acridine, and benz[c]indeno[1,3-mn]acridine; a similar cyclisation of 7-o-chlorophenyldibenz[c,h]acridine leads to dibenz[c,h]indeno[1,3-kl]acridine, whereas the isomeric 14-o-chlorophenyldibenz[a,h]acridine gives a mixture of dibenz[a,h]acridine and benzo[h]phenanthro-[9,10,1-mna]acridine.