New pyrimido[5,4-b]indoles and [1]benzothieno[3,2-d]pyrimidines: High affinity ligands for the α1-adrenoceptor subtypes

Abstract A number of new pyrimido[5,4- b ]indole and [1]benzothieno[3,2- d ]pyrimidine derivatives were synthesized and evaluated for their binding and functional properties at α 1 -adrenergic receptor (α 1 -AR) subtypes. They behaved as potent α 1 -AR antagonists. In binding experiments, some of them (RC24 and RC23) showed very high affinity for the α 1D -AR subtype.