反应详情

0.21 g (0.30 mmol) of (Ph3P)2PdCl2 is added under argan to a solution of 2.5 g (10.05 mmol) of methyl 6′-chloro-2,2′-bipyridine-3-carboxylate (1) in 70 ml of dioxane and the mixture is stirred for 30 min at room temperature. Thereafter, 1.98 g (12.08 mmol) of para-chlorophenylboronic acid, 4.17 g (30.17 mmol) of K2CO3 and 7 ml of H2O are added in succession to the mixture, and the mixture is stirred for 6 hours under reflux and subsequently left to stand overnight at RT. For work-up, the reaction mixture is poured into 100 ml of H2O and extracted repeatedly with CH2Cl2. The combined organic phases are dried over Na2SO4 and concentrated. The residue is purified by column chromatography over silica gel using heptane/ethyl acetate (7:3) as the mobile phase. This gives 2.7 g (82.7%) of product as a solid. M.p.: 120.5° C.; 1H NMR (CDCl3) δ 8.75 (dd, 1H), 8.17 (dd, 1H), 8.00 (m, 2H, C6H4Cl), 7.95 (dd, 1H), 7.92 (dd, 1H), 7.28 (dd, 1H), 7.45 (m, 2H, C6H4Cl), 7.40 (dd, 1H), 3.60 (s, 3H, COOMe).

1. stirringthe mixture is stirred for 6 hours
2. temperatureunder reflux
3. waitsubsequently left
4. waitto stand overnight at RT
5. extractionextracted repeatedly with CH2Cl2
6. dry with materialThe combined organic phases are dried over Na2SO4
7. concentrationconcentrated
8. customThe residue is purified by column chromatography over silica gel