Geron Corporation
Process for preparing imetelstat

Abstract:

The present invention relates to a process for preparing the telomerase inhibitor imetelstat using a 3 steps per cycle phase support bound process comprising the steps of deprotection of the 3'-amino group of the support-bound oligonucleotide, coupling with a 5'-phosphoramidite, and sulfurization with an acyl disulfide, characterized by the absence of an additional capping step in each cycle that is used to prevent unreacted 3'-amino oligonucleotide groups from reacting during subsequent cycles. Imetelstat has formula below. ##STR00001##