22717-55-1

5106-98-9

22717-55-1

1. Synthesis of methyl 4-chloro-2-hydroxybenzoate (2f): 4-chloro-2-hydroxybenzoic acid (200 g, 1.16 mol) was mixed with 40 ml of concentrated hydrochloric acid and added to 400 ml of methanol, followed by addition of sulfuric acid. The reaction mixture was heated to reflux for 20 hours. After completion of the reaction, the solvent was removed by evaporation under reduced pressure. The residue was poured into saturated aqueous Na2CO3 solution and extracted with ether (3 x 500 ml). The organic layers were combined, dried with anhydrous Na2SO4 and the solvent was evaporated to give the crude product 2f (191.6 g, 88.6% yield) as an oil. The product was used for subsequent reactions without further purification.IR (pure) showed absorption peaks: 3150 (OH), 1728 (C=O) and 1678 (C=O) cm-1.1H NMR (CDCl3) δ: 10.27 (br s, 1H, OH), 7.47 (d, 1H, J=8Hz, Ar-H), 6.80 (d, 1H, J=2Hz, Ar-H). 2Hz, Ar-H), 6.63 (d, 1H, Ar-H), 3.85 (s, 3H, OCH3).