Coupling of N-acetyl-D-thioproline (I) with tyrosine methyl ester (II) using EDC and HOBt yielded dipeptide (III). Subsequent alkylation of the tyrosine phenolic group of (III) with 2,6-dichlorobenzyl bromide (IV) and NaH produced the dichlorobenzyl ether (V). The methyl ester group of (V) was finally hydrolyzed employing LiOH in aqueous THF.