Br[C:2]1[CH:7]=[CH:6][N:5]=[C:4]([CH3:8])[CH:3]=1.[NH:9]1[CH:13]=[CH:12][CH:11]=[N:10]1.N1C2C(=CC=C3C=2N=CC=C3)C=CC=1.C([O-])([O-])=O.[K+].[K+]>C1(C)C=CC=CC=1.[Cu]I>[CH3:8][C:4]1[CH:3]=[C:2]([N:9]2[CH:13]=[CH:12][CH:11]=[N:10]2)[CH:7]=[CH:6][N:5]=1
To a mixture of 4-bromo-2-methylpyridine [22282-99-1] (350 mg, 2.05 mmol), 1H-pyrazole (140 mg, 2.05 mmol), 1,10-phenanthroline (74 mg, 0.41 mmol) and K2CO3 (567 mg, 4.1 mmol) in toluene (2 mL), CuI (19 mg, 0.1 mmol) was added and the reaction mixture was heated at 120° C. for 70 h in a sealed tube. The reaction mixture was cooled to rt, quenched with water (50 mL) and extracted with dichloromethane (150 mL). The organic layer was washed with brine and dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure. The crude product was purified flash column chromatography (eluent: 30% ethyl acetate in hexane) to yield the title compound (300 mg, 92%). [1H NMR (300 MHz, CDCl3) ♀ ppm 8.53 (d, 1H), 8.02 (d, 1H), 7.77 (d, 1H), 7.55 (d, 1H), 7.44-7.40 (m, 1H), 6.52 (t, 1H), 2.62 (s, 3H); TLC Rf=0.28 (ethyl acetate/hexane 30:70)].
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