Synthesis of Coumarins

During the last 20 years, the Medicinal Organic Synthesis Research Group, led by Dr. Juri Timonen, has synthesised over one hundred different coumarin structures. These structures include 7-hydroxycoumarins, 7-(2-oxoalkoxy)coumarins, 3-phenylcoumarins and psoralens. Our research has also enhanced the synthetic methodology of 7-hydroxy coumarins by reducing the reaction temperature to room temperature and improving the purity and yield of crude products.[1,2]

In the research group, two different methods have been primarily used to synthetize coumarins skeleton: von Pechman reaction of substituted phenols and b-ketoester and a modified Perkin reaction, which uses phenyl acetic acid and substituted salicyl aldehyde to prepare 3-phenyl coumarins. ked0 Lis

Psoralens are prepared using the cyclization reaction of 7-(2-oxoalkoxy)coumarins in basic conditions. Corresponding 7-(2-oxoalkoxy)coumarins are synthetized using chloroketones for the substitution reaction of phenolic OH-group of 7-hydroxycoumarins.[3]

[1] Timonen, J. M., et al. (2009), Eur. J. Med. Chem., 46(9), 3845-3850.
[2] Timonen, J., et al. (2015), J. Het. Chem., 52(5), 1286-1295.
[3] Timonen, J. M., et al. (2018), J. Het. Chem., 55(11), 2590-2597.