反应详情

2-Chloro-4-{3-chloro-4-[3,3,3-trifluoro-2-hydroxy-1-methyl-2-(3-methyl-2-oxo-2,3-dihydro-benzooxazol-5-yl)-propyl]-phenoxy}-benzoic acid methyl ester (33 mg, obtained in Example 173, step 1) was dissolved in THF (2 mL) followed by the addition of aqueous LiOH solution (1.0M, 0.14 mL). The mixture was stirred for 5 hours at r.t. The reaction mixture was poured into ice/water and acified with 1M aqueous HCl to pH 1. The aqueous layer was extracted three times with ethylacetate. The combined organic layers were washed with brine, dried over Na2SO4, filtered and the solvent was evaporated. The residue was purified by flash chromatography (silica gel, CH2Cl2:MeOH:CH3COOH=100:0:0 to 98:2:0.5) to give the title compound as a light yellow foam. The residual acetic acid was removed by co-evaporation with toluene (10 mg, 31%). MS (neg. ion, m/e)=554.3 [(M−H)−].

1. extractionThe aqueous layer was extracted three times with ethylacetate
2. washThe combined organic layers were washed with brine
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. customthe solvent was evaporated
6. customThe residue was purified by flash chromatography (silica gel, CH2Cl2:MeOH:CH3COOH=100:0:0 to 98:2:0.5)