A novel class of furo [2, 3-d] pyrimidines has been discovered as potent dual inhibitors of Tie- 2 and VEGFR2 receptor tyrosine kinases (TK) and a diarylurea moiety at 5-position shows remarkably enhanced activity against both enzymes. One of the most active compounds, 4- amino-3-(4-((2-fluoro-5-(trifluoromethyl) phenyl) amino-carbonylamino) phenyl)-2-(4- methoxyphenyl) furo [2, 3-d] pyrimidine (7k) is< 3nM on both TK receptors and the activity ...