Synthesis and evaluation of thiazole carboxamides as vanilloid receptor 1 (TRPV1) antagonists

A thiazole derivative, 2-(2,6-dichlorobenzyl)-N-(4-isopropylphenyl) thiazole-4-carboxamide (1), was identified as a TRPV1 antagonist. We synthesized various thiazole analogs and evaluated them for their ability to block capsaicin- or acid-induced calcium influx in TRPV1-expressing CHO cells. The IC50 values of the most potent antagonists were ca. 0.050 μM in these assays.