反应详情

A solution of lithium hydroxide monohydrate (4.41 g, 105.1 mmol) in water (15 mL) was added to a solution of 2-bromo-4-[[(3-hydroxybenzyl)amino]carbonyl]benzoic acid methyl ester (Example 78; 15.30 g, 42.0 mmol) in tetrahydrofuran/methanol (2:1, 21 mL). The solution was concentrated under reduced pressure to remove tetrahydrofuran and methanol and the remaining aqueous solution was extracted with ethyl acetate (15 mL) and the ethyl acetate extract was discarded. The aqueous layer was acidified with 1N hydrochloric acid solution (75 mL) and extracted with ethyl acetate (2×50 mL). The combined organic layers were washed with brine (15 mL), dried (MgSO4), filtered and evaporated to afford 2-bromo-4-[[(3-hydroxybenzyl)amino]carbonyl]benzoic acid (15.1 g, quantitative yield) which was used in a subsequent step without further purification.

1. concentrationThe solution was concentrated under reduced pressure
2. customto remove tetrahydrofuran and methanol
3. extractionthe remaining aqueous solution was extracted with ethyl acetate (15 mL)
4. extractionthe ethyl acetate extract
5. extractionextracted with ethyl acetate (2×50 mL)
6. washThe combined organic layers were washed with brine (15 mL)
7. dry with materialdried (MgSO4)
8. filtrationfiltered
9. customevaporated