1 LIF N-{4-[4-amino-6-(4-methoxyphenyl)furo[2,3-D]pyrimidin-5-yl]phenyl}-N'-[2-fluoro-5-(trifluoromethyl)phenyl]urea 1.000 2 T6E 1-[4-(4-aminothieno[2,3-D]pyrimidin-5-yl)phenyl]-3-[2-fluoro-5-(trifluoromethyl)phenyl]urea 0.750