A series of 2-phenylthiazole analogues were designed and synthesized as potential histone deacetylase 6 (HDAC6) inhibitors based on compound (an HDAC6/tubulin dual inhibitor discovered by us recently) and CAY10603 (a known HDAC6 inhibitor). Among them, compound was the most potent HDAC6 inhibitor with an IC of 31 nM and excellent HDAC6 selectivity (SI = 338 for HDAC6 over HDAC3). also displayed high antiproliferative activity against various cancer cell lines including the HDACi-resistant YCC3/7 gastric cancer cells (IC = 0.