The purinone derivative 6-amino-9-[(3R)-1-(2-butynoyl)-3-pyrrolidinyl]-7-(4-phenoxyphenyl)-7,9-dihydro-8H-purin-8-one hydrochloride has Btk-selective inhibitory activity and, in addition to having excellent metabolic stability, it is a compound that exhibits a high level of solubility and absorption with respect to the free base and can be crystallized, hence it can serve as a therapeutic agent for diseases involving B cells and mast cells.為嘌呤酮衍生物的6-胺基-9-[(3R)-1-(2-丁炔醯基)-3-吡咯啶基]-7-(4-苯氧基苯基)-7,9-二氫-8H-嘌呤-8-酮的鹽酸鹽，由於除具有Btk選擇性抑制活性且代謝穩定性優異外，對游離鹼之溶解性及吸收性優異且為可結晶之化合物的緣故，因此，可成為B細胞及肥胖細胞參與之疾病的治療劑。
