1 547 2,3-diphenyl-N-(2-piperazin-1-ylethyl)furo[2,3-B]pyridin-4-amine 1.000 2 979 5,6-diphenyl-N-(2-piperazin-1-ylethyl)furo[2,3-D]pyrimidin-4-amine 0.935 3 PFQ 2-[(5,6-diphenylfuro[2,3-D]pyrimidin-4-yl)amino]ethanol 0.719