C([N:4]([C:8]1[C:13](Br)=[CH:12][CH:11]=[CH:10][N:9]=1)C(=O)C)(=O)C.N1CCC[C@H]1C(O)=O.C(=O)([O-])[O-].[Cs+].[Cs+].[C:29]([O:35][C:36]([CH3:39])([CH3:38])[CH3:37])(=[O:34])[CH2:30][C:31]([CH3:33])=O>[Cu]I.O1CCOCC1>[CH3:33][C:31]1[NH:4][C:8]2=[N:9][CH:10]=[CH:11][CH:12]=[C:13]2[C:30]=1[C:29]([O:35][C:36]([CH3:39])([CH3:38])[CH3:37])=[O:34]To a 500 mL round-bottom flask that contains N-acetyl-N-(3-bromopyridin-2-yl)acetamide (14.815 g, 57.6 mmol), was added copper(I) iodide (1.098 g, 5.76 mmol), L-proline (1.327 g, 11.53 mmol), cesium carbonate (28.2 g, 86 mmol), then t-butyl acetoacetate (11.47 ml, 69.2 mmol) and dioxane (100 mL). The reaction was vac/purged with N2 3× then fitted with a septum and a N2 inlet and heated overnight at 70° C. The inorganic solids were removed by filtration over celite and the cake was washed with 100 mL EtOAc. This solution was concentrated and the residue was partitioned between 250 mL brine and 250 mL EtOAc. The aq. Layer was further extracted with EtOAc (2×250 mL) and the combined organic layer was dried over Na2SO4, filtered, concentrated and purified by CC using 1:1 EtOAc:Hex as eluent to provide (2.7 g, 20.2%) of tert-butyl 2-methyl-1H-pyrrolo[2,3-b]pyridine-3-carboxylate. LRMS (M+H+) m/z: calc'd 233.28. found 233.1.
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