(S)-tert-butyl 3-(4-aMino-3-(4-phenoxyphenyl)-1H-pyrazolo[3,4-d]pyriMidin-1-yl)piperidine-1-carboxylate

While the (R)-isomer is the primary intermediate for the active drug, the (S)-isomer is often used to produce (S)-Ibrutinib, which serves as a reference compound or impurity in pharmaceutical analysis. The (S)-isomer of tert-butyl 3-(4-amino-3-(4-phenoxyphenyl)-1H-pyrazolo[4-d]pyrimidin-1-yl)piperidine-1-carboxylate serves as a critical intermediate or chiral building block for synthesizing, studying, orpurifying enantiomers of Ibrutinib.