Cesium carbonate → 6-Phenylpyridine-2-carboxylic Acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 6-bromopicolinic acid (2.02 g, 10 mmol), phenyboronic acid (1.22 g, 10 mmol), cesium carbonate (5.00 g) and PdCl2 [(t-Bu)2P(OH)]2 (70 mg, CombiPhos Catalysts, Inc. Princeton, N.J.) in DMF (20 mL) and water (3 mL) was purged with Ar-gas and heated at 110° C. for 24 h. The reaction was incomplete and did not progress further. To the reaction mixture were added EtOAc (200 mL) and 1 N aq. HCl (40 mL). The EtOAc layer was separated, and the aqueous layer was washed with EtOAc (150 mL). The combined EtOAc layers were dried over Na2SO4 and concentrated in vacuo. The residue was purified by preparative HPLC to afford the desired product (350 mg, 18%) as a white solid. 1H NMR (CDCl3) δ 10.45 (s, 1H), 8.18–7.96 (m, 5H), 7.51–7.53 (m, 3H).

Provenance & Evidence