Several pyridine-and pyrimidine-carboxylic acids were synthesized as ligand candidates for retinoid nuclear receptors, retinoic acid receptors (RARs) and retinoic X receptors (RXRs). Although the pyridine derivatives, 6-[(5, 6, 7, 8-tetrahydro-5, 5, 8, 8-tetramethyl-2- naphthalenyl) carbamoyl] pyridine-3-carboxylic acid (2b) and 6-[(5, 6, 7, 8-tetrahydro-5, 5, 8, 8-tetramethyl-2-naphthalenyl) carboxamido] pyridine-3-carboxylic acid (5b) are more ...