[Cl:1][C:2]1[C:10]([O:11][CH3:12])=[CH:9][CH:8]=[C:7]([F:13])[C:3]=1C(O)=O.C(Cl)(C(Cl)=O)=O.[N-:20]=[N+]=[N-].[Na+]>C(Cl)Cl.CN(C=O)C.O>[Cl:1][C:2]1[C:10]([O:11][CH3:12])=[CH:9][CH:8]=[C:7]([F:13])[C:3]=1[NH2:20]To a solution of 2-chloro-6-fluoro-3-methoxy-benzoic acid (2.7 g, 13.2 mmol, 1.0 eq) in a mixture of DCM (20 mL) and DMF (3 drops) at 0° C. was added (COCl)2 (5.0 g, 39.6 mmol, 3.0 eq) dropwise. The reaction mixture was stirred at room temperature for 1 h, and then concentrated to dryness; the residue was dissolved in acetone (20 mL) and added dropwise to a solution of NaN3 (2.6 g, 39.6 mmol, 3.0 eq) in water (15 mL) at 0° C. The reaction was stirred 1 h at 0° C., water (50 mL) was added, then the reaction heated at 70° C. overnight. The acetone was removed by distillation and the aqueous residue extracted with EtOAc. The combined organic extracts were washed with water and brine, dried (Na2SO4), filtered and evaporated in vacuo to give a residue, which was purified by column chromatography (EtOAc:petroleum ether, 0:1 to 1:30) to give the title compound as a yellow oil (0.85 g, 37%).
読み込み中…
