20 ml of DCM were added with 4-chloro-7-hydroxy-6-methoxyquinoline (300 mg, 1.43 mmol; from China Gateway), 1-benzyloxycarbonylamino-1-hydroxymethylcyclopropane (412 mg, 1.87 mmol, 1.3 eq; from China Gateway) and triphenylphosphine (490 mg, 1.87 mmol, 1.3 eq). The resulting solution was dropwise added with a solution of DEAD (378 mg, 1.87 mmol, 1.3 eq) in 3 ml of DCM, keeping the temperature at 0° C. for 2 hours. The mixture was then left at 10° C. for 20 hours, then filtered to recover the unreacted 4-chloro-7-hydroxy-6-methoxyquinoline. The filtrate was evaporated under vacuum and the resulting residue was added with 20 ml of 95% EtOH and left under stirring for 30 min. The solid was collected by filtration, washed with 5 ml of 95% EtOH and dried under vacuum to give 1-[(4-chloro-6-methoxyquinolin-7-yloxy)methyl]-N-benzyloxycarbonyl-1-aminocyclopropane (273 mg; yield: 46%).
