3-Amino-2-methylbenzoic acid methyl ester → 3-Hydroxy-2-methylbenzoic Acid

Participants

Reaction Steps

A solution of 20.6 g (0.125 mol) of methyl 3-amino-2-methylbenzoate in 150 mL of HOAc and 25 mL of conc. H2SO4 was cooled in ice and diazotized by the dropwise addition of a solution of 8.7 g (0.125 mol) of NaNO2 in 50 mL of H2O. After stirring for 15 minutes, the diazonium solution was added dropwise to a boiling solution of 200 mL of 50% H2SO4, and the refluxing continued for 15 minutes after the addition was complete. The mixture was diluted with H2O and extracted twice with Et2O. The Et2O was washed 5 times with H2O, then with saturated NaCl. Drying over MgSO4 and removal of the solvent under reduced pressure left 17.98 g (94.4% yield) of the product as a tan solid, mp 137-140° C. The structure was confirmed by NMR spectroscopy.

Provenance & Evidence