Histamine analogues. 32nd communication: synthesis and pharmacology of sopromidine, a potent and stereoselective isomer of the achiral H2-agonist impromidine

Abstract Synthesis and pharmacology of sopromidine (( R )-7) and ( S )- 7 , 2 position isomers of impromidine derived from the enantiomeric α-methylhistamines, are reported. The enantiomers of 7 show high stereoselectivity at the atrial H 2 -receptor of the guinea-pig. ( R )- 7 is revealed to be a full H 2 -agonist with 7.4-fold potency relative to histamine, while ( S )- 7 is a competitive H 2 -antagonist.