反应详情

Acetyl chloride (14.7 ml, 5 eq.) is added slowly to an ice cooled suspension of AlCl3 (27.7 g, 5 eq.) in dry CH2Cl2 (125 ml). The reaction is stirred until most of the solid is dissolved, then 5-methyl salicylic acid 236 (6.31 g, 41 mmol) is added. The reaction is stirred at 0° C. for 1.5 hr, then at room temperature for 1.5 hr. The reaction is poured onto ice, diluted with Et2O, and washed with water, brine, dried (MgSO4). Concentration in vacuo afforded a slowly crystallizing oil. Recrystallization (CH2Cl2/hexanes) yielded pure 3-Acetyl-5-methyl salicylic acid (Example 529, Table IIIa) as 3.29 g of off white powder (41% recrystallized yield).

1. temperaturecooled
2. dissolutionis dissolved
3. stirringThe reaction is stirred at 0° C. for 1.5 hr
4. additionThe reaction is poured onto ice
5. washwashed with water, brine
6. dry with materialdried (MgSO4)
7. concentrationConcentration in vacuo
8. customafforded
9. customa slowly crystallizing oil
10. customRecrystallization (CH2Cl2/hexanes)