Cyanoguanidine bioisosteres in potassium channel openers: Evaluation of 3,4-disubstituted-1,2,5-thiadiazole-1-oxides

Bioisosteric substitution of the cyanoguanidine group found in pinacidil (1) with a 3,4-diamino-1,2,5-thiadiazole-1-oxide moiety and replacement of the 4-aminopyridine group with a 3,5-dichlorophenyl group has resulted in a new structural class of potassium channel opener (PCO).