Preparation and fungitoxicity of some dibromo-8-quinolinols

2,5-, 3,5-, 3,6-, 3,7-, 4,5-, 5,6-, 5,7-, and 6,7-dibromo-8-quinolinols were prepared and tested against six fungi (Aspergillus niger, Aspergillus oryzae, Myrothecium verrucaria, Trichoderma viride, Mucor cirinelloides, and Trichophyton mentagrophytes) in Sabouraud dextrose broth. Most of the compounds were strongly antifungal, inhibiting five of the fungi below 1 mug/cm(3), but were somewhat less fungitoxic than the corresponding chloro analogues. M. cirinelloides was not inhibited by any of the compounds except 4,5-dibromo-8-quinolinol. This high level of fungitoxicity is attributed to intramolecular synergism.