(4-Chloro-2-fluoro-5-methoxyphenyl)boronic acid → 2-(4-Chloro-2-fluoro-5-methoxyphenyl)imidazo[1,2-a]pyridine

Participants

Reaction Steps

A mixture of 0.8 g (4.1 mmol) of 2-bromoimidazo[1,2-a]pyridine, 0.8 g (4.2 mmol) of 4-chloro-2-fluoro-5-methoxyphenylboronic acid, and 0.2 g (0.28 mmol) of bis(triphenylphosphine)palladium(II) chloride were heated in 30 ml of glyme at reflux for 2 h. The reaction mixture was partitioned between 250 ml of ethyl acetate and 100 ml of water and the separated organic layer washed with brine and dried over magnesium sulfate. On evaporating in vacuo, the remaining residue was flash chromatographed on silice gel (1:1 hexane/ethyl acetate) to afford 0.7 g of the title compound (m.p. 139°-141° C.). NMR (CDCl3, 400 MHz): δ4.03 (s, 3H), 6.81 (t, 1H), 7.21 (m, 2H), 8.63 (d, 1H), 7.92 (d, 1H), 8.04 (s, 1H), 8.14 (d, 1H).

Provenance & Evidence