Cl[C:2]1[N:7]=[C:6]([O:8][CH3:9])[C:5]([N+:10]([O-:12])=[O:11])=[CH:4][CH:3]=1.C([Sn](CCCC)(CCCC)[C:18]1[O:19][CH:20]=[CH:21][N:22]=1)CCC.O1CCOCC1.O>C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.C(OCC)(=O)C>[CH3:9][O:8][C:6]1[C:5]([N+:10]([O-:12])=[O:11])=[CH:4][CH:3]=[C:2]([C:18]2[O:19][CH:20]=[CH:21][N:22]=2)[N:7]=1An oven-dried resealable Schlenk tube was charged with 6-chloro-2-methoxy-3-nitropyridine (0.50 g, 2.6 mmol), 2-tributylstannanyloxazole (1.20 g, 3.4 mmol) and 1,4-dioxane (10 mL) and then subjected to several cycles of evacuation-backfilling with argon. Tetrakis(triphenylphosphine)palladium (0.18 g, 0.16 mmol) was then added and, after three new cycles of evacuation-backfilling with argon, the Schlenk tube was sealed and the mixture was stirred and heated in an oil bath to 110° C. After stirring overnight, water and ethyl acetate were added and the organic layer was washed with water, dried (MgSO4) and evaporated. The residue was purified by flash chromatography (2:1 hexanes/ethyl acetate) to give the title compound (0.38 g, 67%) as a yellow solid.
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