[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[NH:11][C:10]3[CH:12]=[CH:13][CH:14]=[CH:15][C:9]=3[C:8](=O)[NH:7][C:6]=2[CH:17]=1.P(Cl)(Cl)([Cl:20])=O.C([O-])([O-])=O.[Na+].[Na+]>C1C=CC=CC=1>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[NH:11][C:10]3[CH:12]=[CH:13][CH:14]=[CH:15][C:9]=3[C:8]([Cl:20])=[N:7][C:6]=2[CH:17]=1A mixture of amide 9 (1.39 g, 5.70 mmol), phosphorus oxychloride (1.6 mL, 17.1 mmol) and N-dimethylaniline (2.9 mL, 22.8 mmol) in benzene (10 mL) was heated at reflux for 2 hours. The reaction mixture was then cooled to room temperature and excess of phosphorus oxychloride, N-dimethylaniline and benzene were removed at reduced pressure. The resulting residue was dissolved in dioxane (20 mL) and 2 M Na2CO3 (30 mL 0.06 mol) and then heated at 80° C. for 1 hour. The reaction mixture was cooled to room temperature and dioxane was removed at reduced pressure and the resulting aqueous solution was extracted with EtOAc (30 mL). The organic phase was washed with water, brine, dried (Na2SO4), filtered and solvent evaporated. The resulting crude residue was purified by column chromatography (10% ethyl acetate in hexanes) to afford title compound 10 (869 mg, 58%) as an orange solid. LRMS (ESI): (calc) 262.01 (found) 263.1 (MH)+.
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