Sodium Carbonate → 3-[3-(2-Cyanothien-3-yl)phenyl]imidazo[1,2-alpha]pyridine-7-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

3-Bromoimidazo[1,2-α]pyridine-7-carboxylic acid methyl ester (0.63 g, 2.47 mmol) and 3-[3-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)phenyl]thiophene-2-carbonitrile (0.55 g, 1.76 mmol) were suspended in 1,2-dimethoxyethane (10 ml) and 2N sodium carbonate solution (5 ml) and degassed with nitrogen for 30 min before addition of tetrakis(triphenylphosphine)palladium(0) (0.14 g, 0.12 mmol). The mixture was heated at 80° C. for 18 h then cooled to room temperature. The mixture was partitioned between ethyl acetate (100 ml) and water (50 ml). The organic layer was washed with brine, dried over sodium sulfate and pre-adsorbed onto silica gel. Purification by silica gel chromatography eluting with dichloromethane/methanol/conc. ammonia (gradient 99:1:0.1 through to 97:2:0.2) gave the title compound (0.59 g, 94%) as pale brown needles. 1H NMR (400 MHz, CDCl3) δH 3.98 (3H, s), 7.35 (1H, d, J 5), 7.48 (1H, dd, J 7 and 2), 7.65-7.75 (3H, m), 7.93 (2H, m), 8.43 (1H, s), 8.54 (1H, dd, J 7 and 1); m/z (ES+) 360 (M++H).

Provenance & Evidence