反应详情

To the organic solution of methyl 2,4-dichloro-5-(3-fluoropyridin-2-yl)benzoate (from Preparation 43A, 1.95 mol) was added a solution of sodium hydroxide (234 g, 5.85 mol) in water (2.8 L) and the reaction stirred at room temperature for 1 hour. The mixture was concentrated in vacuo to remove organic solvents to a volume of approximately 5 L. The remaining aqueous phase was washed with ethyl acetate (3×2 L) and then acidified to pH2 with aqueous HCl (2 M). The resulting precipitate was collected by filtration and washed with water (2 L). The solid was ground to a fine powder and slurried with diethyl ether (2.5 L) and filtered to afford the title compound as an off-white solid (181 g).

1. concentrationThe mixture was concentrated in vacuo
2. customto remove organic solvents to a volume of approximately 5 L
3. washThe remaining aqueous phase was washed with ethyl acetate (3×2 L)
4. filtrationThe resulting precipitate was collected by filtration
5. washwashed with water (2 L)
6. filtrationfiltered