L-[ (3R) -3-[4-amino-3- (4-phenoxyphenyl) -lHpyrazolo [3,4-d]pyrimidin-l-yl]-l-piperidinyl]-2-propyn-l-one

L-[ (3R) -3-[4-amino-3- (4-phenoxyphenyl) -lHpyrazolo[3,4-d]pyrimidin-l-yl]-l-piperidinyl]-2-propyn-l-one, is a derivative of the first-in-class covalent BTK inhibitor ibrutinib. Ibrutinib inhibits B-cell proliferation and survival by irreversibly binding the protein Bruton's tyrosine kinase (BTK) . B cell cancers are directly affected by this since the B-cell receptor pathway is often aberrantly active.