The present invention relates to the use of ( R ) -4- (3 - (( S ) -1- (4-amino-3-methyl-1H-pyrazolo [3,4 yl) ethyl) -5-chloro-2-ethoxy-6-fluorophenyl) pyrrolidin-2-one as well as the salt forms and intermediates associated therewith to provide.본원은 억제제 포스포이노시티드 3-키나제-델타 (PI3Kδ)로서 유용한 (R)-4-(3-((S)-1-(4-아미노-3-메틸-1H-피라졸로[3,4-d]피리미딘-1-일)에틸)-5-클로로-2-에톡시-6-플루오로페닐)피롤리딘-2-온, 뿐만 아니라 그것과 관련된 염 형태 및 중간체를 제조하는 과정을 제공한다.