Sodium Carbonate → tert-butyl 4-(3,5-bis(trifluoromethyl)phenyl)-5,6-dihydropyridine-1(2H)-carboxylate

関与物質

反応手順

A solution of tert-butyl 4-(((trifluoromethyl)sulfonyl)oxy)-5,6-dihydropyridine-1(2H)-carboxylate (2, 1.10 g, 3.32 mmol) and (3,5-bis(trifluoromethyl)phenyl)boronic acid (1.42 g, 3.32 mmol), Pd(PPh3)4 (0.38 g, 0.33 mmol) and 2 M Na2CO3 (20 mL) in DME (50 mL) was heated at 80° C. for 6 h. The mixture cooled to ambient temperature, and the resulting solids were removed by filtration through a Celite pad. The filtrate was washed brine solution (4×50 mL) and concentrated under reduced pressure. The resulting residue was chromatographed over silica gel (Isco CombiFlash Rf unit, 40 g Redisep column, 0% to 80% EtOAc in hexanes) to provide tert-butyl 4-(3,5-bis(trifluoromethyl)phenyl)-5,6-dihydropyridine-1(2H)-carboxylate (18) as a yellow oil (0.891 g, 68%): 1H NMR (300 MHz, DMSO-d6) δ 8.09-8.04 (m, 2H), 8.00-7.96 (m, 1H), 6.53-6.42 (m, 1H), 4.09-4.00 (m, 2H), 3.55 (t, J=5.7 Hz, 2H), 2.60-2.52 (m, 2H), 1.43 (s, 9H).

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