Cesium carbonate → 2-Hydroxy-5-phenylnicotinic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-bromo-2-hydroxynicotinic acid (436 mg, 2.00 mmol, Syn. Comm., 19 (3&4), 553–559 (1989)), phenylboronic acid (248 mg, 2.03 mmol), Cs2CO3 (1.20 g) and PdCl2 [(t-Bu)2P(OH)]2 (170 mg, CombiPhos Catalysts, Inc. Princeton, N.J.) in DMF (10 mL) and water (1.0 mL) was purged with Ar gas and heated at 110° C. for 6 h. Additional phenylboronic acid (75 mg) was added and the mixture was heated at 110° C. for 5 h. To the reaction was added TFA (3 mL), and the mixture was concentrated in vacuo to a volume of ˜12 mL. The mixture was purified by preparative HPLC to afford the desired product (78 mg, 18%). 1H NMR (DMF-d7) δ 14.8 (br s, 1H), 13.8 (br s, 1H), 8.73 (s, 1H), 8.46 (s, 1H), 7.74 (d, 1H, J=7.2 Hz), 7.53–7.42 (m, 3H), 5.81 (s, 1H).

Provenance & Evidence