(Rac)-IBT6A hydrochloride is a racemic mixture comprising IBT6A hydrochloride, which itself is an impurity of Ibrutinib. This compound plays a role in the synthesis of both the IBT6A Ibrutinib dimer and the IBT6A adduct [1]. Ibrutinib, to which IBT6A is related, acts as a selective and irreversible inhibitor of Bruton's tyrosine kinase (Btk), exhibiting an inhibitory concentration (IC50) of 0.5 nM [2].