Methanol → Methyl 5-methylsalicylate

Beteiligte Stoffe

Reaktionsschritte

5-Methylsalicylic acid was reacted with methanol and sulphuric acid by the general method of Brunner (Monatsh. 1913, 34, 916) to give methyl 5-methylsalicylate, b.p. 115°-116° C./10 mmHg. This ester (12.0 g) was heated together with benzyl chloride (9.1 g) and anhydrous potassium carbonate (5.0 g) in dry sulpholane (90 ml) at 100° C. for 22 hours. The mixture was then poured into a mixture of ice and water (1200 ml) to give crude methyl 2-benzyloxy-5-methylbenzoate (17.6 g). This ester (4.3 g) was heated at reflux with aqueous sodium hydroxide solution (2N; 100 ml) for 2 hours and the mixture was then cooled, diluted with water, and acidified to pH 2 by treatment with concentrated hydrochloric acid to give 2-benzyloxy-5-methylbenzoic acid (3.65 g), m.p. 98°-100° C.

Herkunft & Nachweise