Methanol → Methyl p-aminosalicylate

Participants

Reaction Steps

2-Hydroxy-4-aminobenzoic acid (100 g, 0.654 mole) was suspended in freshly distilled methanol (1 1), concentrated sulphuric acid (50 ml) was slowly added and the reaction mixture refluxed under nitrogen until all the material was dissolved (24-48 hours), after which it was concentrated to about 350 ml by evaporation, in vacuo. The concentrate was neutralized with 33% sodium hydroxide and 1M sodium hydrogen carbonate and extracted with ether (3×250 ml), the ether layer was washed with 1M sodium hydrogen carbonate (2×50 ml) and water (2×50 ml), dried over anhydrous magnesium sulphate (20 g), and the ether removed by evaporation, in vacuo. The product was dried, in vacuo, to give the title compound (67.5 g, 62%), m.p. 120°-122° C. Found (Calc. for C8H9NO3) C 57.57 (57.48), H 5.41 (5.39), N 8.22 (8.38).

Provenance & Evidence