765913-41-5Relevant articles and documents
Enantioselective synthesis of (R)-(-)-praziquantel (PZQ)
Roszkowski, Piotr,Maurin, Jan K.,Czarnocki, Zbigniew
, p. 1415 - 1419 (2006)
Praziquantel 8 (2-cyclohexylcarbonyl-1,2,3,6,7,11b-hexahydro-4H-pyrazino[2,1-a]isoquinoline-4-one), a powerful anti-worm drug, has been synthesized in its enantiopure form via asymmetric transfer hydrogenation according to the Noyori protocol. Initially, the reduction of prochiral imine 4 afforded product 5 in 62% ee, but a single crystallization amplified the enantiomeric purity to 98% ee. The final (R)-(-)-praziquantel 8 was prepared in three subsequent steps in 56% chemical yield.
Total synthesis of (-)-praziquantel: An anthelmintic drug
Ma, Chen,Zhang, Qian-Feng,Tan, Ye-Bang,Wang, Long
, p. 186 - 187 (2007/10/03)
The optically pure (-)-praziquantel was synthesised using phenylethylamine as starting material in 12% overall yield. The key step was achived by a chiral auxiliary mediated Pictet-Spengler reaction.