Synthesis of a Glycogen Synthase Kinase-3 Inhibitor

Significance Glycogen synthase kinase-3 (GSK-3) is involved in signaling from the insulin receptor and inhibitors of it are expected to lower plasma glucose similar to insulin. It is under development for the treatment of type 2 diabetes. The target bisarylmaleimide was synthesized in seven steps in 33% overall yield from 5-fluoroindole ( A ).