Methanol → Benzoic acid, 5-chloro-2-hydroxy-, methyl ester

Participants

Reaction Steps

A mixture of 5-chloro-2-hydroxybenzoic acid (100 g, 0.57 mol), 20 ml of conc. H2SO4 and 200 ml of dry methanol was heated under reflux for 22 hours. An additional 5 ml of conc. H2SO4 was then added and the solution heated for an additional 24 hours. The solvent was evaporated under reduced pressure and the resulting residue poured into aqueous saturated Na2CO3 and then extracted with CH2Cl2 (2×400 ml). The organic layers were combined, dried over anhydrous Na2SO4, and evaporated to give the desired compound as a white solid (100.5 g, 94.8% yield), mp 44°-46° C. IR (nujol) 1680 (ester) cm-1. NMR (CDCl3) δ 10.60 (s, 1H, OH), 7.73 (d, 1H, JBC =3 Hz HC), 7.33 (d of d, 1H, JAB =9 Hz, HB), 6.87 (d, 1H, HA), and 3.92 (s, 3H, CH3).

Provenance & Evidence