Ionic liquid-promoted multi-component reaction: novel and efficient preparation of pyrazolo[3,4-b]pyridinone, pyrazolo[3,4-b]-quinolinone and their hybrids with pyrimidine nucleoside - Xinying Zhang; Dongfang Li; Xuesen Fan; Xia Wang; Xiaoyan Li; Guirong Qu; Jianji Wang (Molecular Diversity, 2010)