Disclosed herein is a process for the preparation of a compound of formula (I), in particular a compound of formula (I-S), wherein the substituents are as defined within the specification, wherein the process comprises reacting a compound of formula (V) with a compound of formula (VI) in a first organic solvent and in the presence of a coupling agent system to yield the corresponding compound of formula (VII), de-protecting the compound of formula (VII), to yield the corresponding compound of formula (VIII) and followed by reacting the compound of formula (VIII) with a compound of formula (IX) in a second organic solvent to yield the corresponding compound of formula (I).
