3-Methylsalicylic Acid → 2-hydroxy-N-(6-methoxypyridin-2-yl)-3-methylbenzamide

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

10 ml of thionyl chloride are added to 1.47 g (16.11 mmol) of 2-hydroxy-3-methylbenzoic acid and the reaction mixture is heated at 90° C. for 2 h. The reaction medium is concentrated to dryness by azeotroping with toluene. The residue is then put into solution in 10 ml of pyridine, to which 600 mg (4.83 mmol, 1 eq) of 2 methoxypyridin-6-amine are added dropwise, and the reaction medium is left stirring at room temperature for 1 h 30 mins. 30 ml of 1M sodium hydroxide (19.34 mmol, 4 eq) are added and the reaction medium is heated at 60° C. for 16 h. The reaction medium is diluted with 100 ml of ethyl acetate, the aqueous phase is extracted and washed with 50 ml of ethyl acetate. The aqueous phase is then acidified at 0° C. with 37% HCl dropwise to pH=4. The organic phases are extracted twice with 50 ml of ethyl acetate and then they are washed twice with 50 ml of water. The organic phases are concentrated to dryness and the residue is purified by chromatography over silica, eluting with a heptane/ethyl acetate (1/1) mixture. 2-Hydroxy-N-(6-methoxypyridin-2-yl)-3-methylbenzamide is obtained in the form of a white solid.

Herkunft & Nachweise