Provided herein is a process for the preparation of N-(5-tert-butyl-isoxazol-3-yl)- N-{4-[7-(2-morpholin-4-yl-ethoxy)imidazo[2,1-b][1,3]benzothiazol-2-yl]phenyl}urea,or apharmaceutically acceptable salt, solvate, hydrate, or polymorph thereof. N-(5-tert- Butyl-isoxazol-3-yl)-N-{4-[7-(2-morpholin-4-yl-ethoxy)imidazo[2,1-b][1,3]benzothiazol-2-yl]phenyl} urea is useful for treating, preventing, and/or managing diseasesor conditions,including but not limited to, proliferative diseases, FLT-3 mediated diseases,and cancers. N-(5-tert-Butyl-isoxazol-3-yl)N-{4-[7-(2-morpholin-4-yl- ethoxy)imidazo[2,1-b][1,3]benzothiazol-2-yl]phenyl} urea is represented by the structure: