p-quinone methides as geometric analogues of quinolone carboxylate antibacterials

In an attempt to examine the role of the N(1)-alkyl or -aryl moiety of the quinolone antibacterials, several quinone methides such as perinaphthindenone carboxylates ( ) were synthesized as 1-carba(sp2) analogues of the quinolone structure, and found to have no antibacterial activity. These results together with literature information are interpreted as the necessity of at least one nitrogen atom at the position of 1, 3, 4a, 6 or 8 in the quinolone-like skeleton for the antibacterial activities.