2-aminothiazoles:: A new class of agonist allosteric enhancers of A1 adenosine receptors

This report describes the synthesis and structure-activity relationships of a new class of A(1) adenosine receptor agonist allosteric enhancers, 2-aminothiazolium salts. The EC50 of compounds 6a, 6b, 7, and 8 were 0.3, 4.5, 3.8, and 1.2 muM, substantially lower than that of the 'Gold Standard' 2-amino-3-benzoyl thiophene (PD 81,723), which has an EC50 of 38 muM. (C) 2002 Elsevier Science Ltd. All rights reserved.