Sodium Carbonate → 3-[3-(2-Ethoxy-3,5-diisopropyl-phenyl)-imidazo[1,2-a]pyridin-6-yl]-but-2-enoic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

3-(3-Iodo-imidazo[1,2-a]pyridin-6-yl)-but-2-enoic acid methyl ester (168 mg, 0.49 mmol), tetrakis(triphenylphosphine)palladium(0) (57 mg, 0.05 mmol), followed by 2M sodium carbonate solution (1 ml) were added to a solution of 2-ethoxy-3,5-diisopropyl-phenyl-boronic acid (246 mg, 0.98 mmol) (see Example 5, step B) in toluene (10 mL). The reaction mixture was heated to 90° C. overnight, then poured into brine (20 mL) and extracted with ethyl acetate (2×20 mL). The organic layers were combined, dried over MgSO4 and concentrated in vacuo. The residue was purified by chromatography (chromatotron, 2μ plate, 50% ethyl acetate in hexanes) to give a 3-[3-(2-ethoxy-3,5-diisopropyl-phenyl)-imidazo[1,2-a]pyridin-6-yl]-but-2-enoic acid methyl ester as a yellow oil (157.5 mg, 76%). 1H NMR (250 MHz, CDCl3): δ 8.19 (bs, 1H), 7.75 (s, 1H), 7.68 (d, 1H, J=9.4), 7.42 (dd, 1H, J=9.4, J=1.2), 7.25 (d, 1H, J=2.5), 7.15 (d, 1H, J=2.5), 6.24 (d, 1H, J=0.62), 3.28 (s, 3H), 3.44 (m, 1H), 3.35 (q, 2H, J=8.1), 2.97 (m, 1H), 2.59 (d, 3H, J=0.62), 1.35 (s, 3H), 1.33 (s, 3H), 1.32 (s, 3H), 1.30 (s, 3H), 1.29 (t, 3H, J=8.1). MS [EI+] 421 (M+1)+.

Provenance & Evidence