Potassium Phosphate, Tribasic → 3-[3-(7-Formylimidazo[1,2-alpha]pyridin 3-yl)phenyl]thiophene-2-carbonitrile

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Reaction Conditions

Reaction Steps

3-Bromoimidazo[1,2-α]pyridine-7-carboxaldehyde (1.15 g, 5.16 mmol), potassium phosphate (2.19 g, 10.31 mmol) and 3-[3-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)phenyl]thiophene-2-carbonitrile (2.58 g, 8.26 mmol) were dissolved in N,N-dimethylacetamide (15 ml) and the mixture degassed with N2 for 15 min. Tetrakis(triphenylphosphine)pallidum(0) (0.30 g, 0.26 mmol) was added and the mixture heated at 80° C. for 18 h. The mixture was allowed to cool to room temperature, diluted with water (20 ml) and saturated sodium hydrogencarbonate solution (20 ml), then extracted with ethyl acetate (2×75 ml). The combined organic fractions were washed with brine (40 ml), dried over anhydrous sodium sulfate and evaporated to give a black oil. The oil was purified by silica gel chromatography eluting with dichloromethane and 1% conc. ammonia on a gradient of methanol (1-2%). The solid obtained was triturated with diethyl ether which gave the title compound (1.15 g, 68%) as a white powder. Oxalate salt, white powder. 1H NMR (360 MHz, d6-DMSO) δH 7.30 (1H, dd, J 7 and 1), 7.70-7.88 (4H, m), 8.08 (1H, s), 8.16-8.22 (2H, m), 8.44 (1H, s), 8.78 (1H, d, J 7), 10.05 (1H, s); m /z (ES+) 330 (M++H).

Provenance & Evidence