[CH3:1][O:2][C:3]1[CH:8]=[C:7]([Cl:9])[N:6]=[C:5]([C:10]([OH:12])=O)[CH:4]=1.C1N=C[N:15](C(N2C=NC=C2)=O)C=1.[NH4+].[OH-].O>CN(C=O)C.C(Cl)Cl>[Cl:9][C:7]1[N:6]=[C:5]([C:10]([NH2:15])=[O:12])[CH:4]=[C:3]([O:2][CH3:1])[CH:8]=1
To a solution of 4-methoxy-6-chloro picolinic acid (25 mmol) in anhydrous DMF (48 mL) was added CDI (27.5 mmol) at 0° C. The reaction mixture was stirred for 5 min in an ice-bath and then stirred at room temperature. After the reaction was completed, NH4OH (190 mL) was added and the reaction mixture was stirred at room temperature for 6 hrs. The mixture was partioned between H2O (200 mL) and DCM (300 mL). The organic layer was washed with H2O and brine, dried over MgSO4, filtered, and concentrated under reduced pressure. The crude was purified by silica gel chromatography (eluent: DCM/CH3OH) to give compound 18 as a beige solid in 61% yield. MS (ESI, EI+): m/z=187.14 (MH+).
Loading…
