4-(Chloromethyl)thiazole hydrochloride and its derivatives can be used to prepare 4-thiazole carboxylic acid. It has been shown that in the study of synthesis of conformationally restricted RGD-containing integrin ligands by efficient solid-phase intramolecular thioalkylation, the reaction of S-nucleophiles with the newly generated N-terminal 4-chloromethyl thiazoles afforded the desired cyclic RGD product 5 with high purity and good overall yield[1].
[1] ADEL NEFZI Jason E F. N-terminus 4-chloromethyl thiazole peptide as a macrocyclization tool in the synthesis of cyclic peptides: application to the synthesis of conformationally constrained RGD-containing integrin ligands[J]. Tetrahedron Letters, 2011. DOI:10.1016/j.tetlet.2010.12.043.
