A series of disubstituted catechol derivatives was synthesized and tested as potential COMT inhibitors. The most active compounds were more than loo0 times more potent (ICm= 3-6 nM) in vitro than the known COMT inhibitor, 3', 4'-dihydroxy-2-methylpropiophenone (U 0521, ICm= 6000 nM). The new compounds were also highly selective COMT inhibitors with no activity against other essential enzymes involved in the synthesis and metabolism of ...