反应详情

温度

90 °C

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.

1. concentrationThe reaction medium is concentrated to dryness
2. customby azeotroping with toluene
3. additionare added dropwise
4. waitthe reaction medium is left
5. temperaturethe reaction medium is heated at 60° C. for 16 h
6. extractionthe aqueous phase is extracted
7. washwashed with 50 ml of ethyl acetate
8. customis then acidified at 0° C. with 37% HCl dropwise to pH=4
9. extractionThe organic phases are extracted twice with 50 ml of ethyl acetate
10. washthey are washed twice with 50 ml of water
11. concentrationThe organic phases are concentrated to dryness
12. customthe residue is purified by chromatography over silica
13. washeluting with a heptane/ethyl acetate (1/1) mixture