100 Gram Scale Synthesis of a Key Intermediate of Matrix Metalloproteinase Inhibitor in a Continuous-Flow System Based on a Copper-Free Sonogashira Reaction Using an Ionic Liquid as a Catalyst Support

The key intermediate of matrix metalloproteinase (MMP) inhibitor was synthesized using a flow microreactor for a copper-free Sonogashira coupling reaction in an ionic liquid. The ionic liquid [emim]NTf 2 was used as a solvent and a catalyst support. A 100 g scale synthesis was achieved in combination with a flow-extraction/catalyst-recycling system, in which the ionic liquid containing the palladium catalyst was continuously recycled.