CA2710726A1 — Synthesis of treprostinil and intermediates useful therein

USPTO Abstract

Treprostinil is prepared by a process which involves Pauson - Khan cyclization of an an alkene-substituted, alkyne-substituted benzene corresponding to formula: (see above formula) where PMB represents para-methoxybenzyl protecting group and R1 and R2 are alcohol protecting groups. Following cyclization, the resulting compound can be subjected to several chemical transformations followed by alkylation, hydrolysis and salt formation to yield treprostinil sodium. The use of para-methoxybenzyl group as the phenolic protecting group confers several process advantages that result in simplified purification of the final product and improved yields.