1H-pyrazolo[3,4-d]pyrimidin-4-amine is a heterocyclic organic compound, which has the biological activity of reducing serum cholesterol in rats. This product can be used as a pharmaceutical intermediate for the synthesis of irutinib. Irutinib is a small molecule Btk inhibitor, which can covalently bind with cysteine residues in Btk active center to inhibit its activity. It is used in the treatment of mantle cell lymphoma.