2H-​Imidazole-​2-​thione, 5-​(aminomethyl)​-​1-​[(2R)​-​5,​7-​difluoro-​1,​2,​3,​4-​tetrahydro-​2-​naphthalenyl]​-​1,​3-​dihydro-​, hydrochloride (1:1)

(R)-Nepicastat Hydrochloride is the R-enantiomer of Nepicastat Hydrochloride; a novel, potent, selective, and orally active inhibitor of dopamine-β-hydroxylase. The R-enantiomer was shown to be approximately 2-3 times less potent than Nepicastat Hydrochloride.