New and Practical Synthesis of GS-441524, the Key Intermediate of Remdesivir

Abstract
A new and practical synthesis of GS-441524, the key intermediate for remdesivir, is developed. 4-Amino-7-iodopyrrolo[2,1-f][1,2,4]triazine is protected by DMF-DMA, and reacted with 2,3,5-tri-O-benzyl-D-ribonolactone to give the product in 61% isolated yield. The next cyanation and debenzylation are carried out at -30 degrees C successively in 67% yield over two steps with >99% purity (HPLC). Purification methods of the intermediates and the final product involved in the route are developed.
Keywords