Development ofa Commercial Ready Process for <b>TNG908</b>: A Potent, Selective,and Brain-Penetrant MTA-CooperativePRMT5 Inhibitor

<b>TNG908</b> is a potent, selective, and brain-penetrant MTA-cooperative PRMT5 inhibitor for the treatment of <i>MTAP</i>-deleted tumors. We describe here the chemical process development for the synthesis of <b>TNG908</b> and the improvements that were achieved over the medicinal chemistry route with much higher yields and better purities. This commercial ready process is convergent, diastereoselective, safe, reproducible, and robust. A total of eight GMP batches have been successfully manufactured, resulting in high-purity API meeting all specifications.