Desmorpholinyl Quizartinib-PEG2-COOH incorporates a ligand for FLT-3, and a PEG-based PROTAC linker. Desmorpholinyl Quizartinib-PEG2-COOH can be used in the synthesis of PROTAC FLT-3 degrader 1 (HY-114323). PROTAC FLT-3 degrader 1 is a PROTAC FLT-3 internal tandem duplication (ITD) degrader with an IC50 0.6 nM[1].