6-Hydroxy-2-naphthoic acid → Methyl 6-hydroxy-2-naphthoate

Participants

Reaction Steps

6-Hydroxy-2-naphthoic acid (5.0 g, 26.6 mmol) was dissolved in 125 mL of methanol and refluxed with 6 drops of conc. H2SO4 for 36 hours. TLC analysis (SiO2, 10:1 CHCl3 /MeOH) revealed only a trace of the acid left. The solution was cooled partially and concentrated to dryness on a rotary evaporator. The solid residue was dissolved in 200 mL of ether and washed successively with 100 mL of saturated aq. NaHCO3 and brine. Drying over MgSO4 and evaporating the solvent left 4.6 g of (85.5%) slightly yellow solid which showed only one spot on TLC. The material is sufficiently pure for use in subsequent reactions but may be purified further by recrystallization from ether affording a white solid mp 169°-169.5° C.; 1H NMR delta 3.976 (s, 3H), 5.3 (br. s, 1H), 7.16-8.54 (m, 6H); IR (KBr) 3370, 1680, 1630, 1435, 1310, 1210 cm-1. ##STR27##

Provenance & Evidence