Table 19. Dainippon SAR at the quinolone 6- and 8-positions suggesting that co-planarity of the 2-thiazole ring is a determent of potency for this scaffold.

Compound	R6	R8	P388 cells CC50 (μg/ml)a
130	CF	N	0.02
145	N	N	0.05
146	CF	CH	>10
147	CF	CF	55

^aMurine lymphocytic leukemia cell line