反应详情

A mixture of 4-[5-(3,5-dichloro-phenyl)-4-(1-hydroxy-ethyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-2-methyl-benzoic acid methyl ester (Example 7.1) (0.242 g, 0.51 mmol), lithium hydroxide monohydrate (0.06 g, 1.4 mmol), tetrahydrofuran (5 ml) and water (5 ml) was stirred at ambient temperature for 2 days. Then further portions of lithium hydroxide monohydrate were added to complete the reaction. In total, 545 mg of lithium hydroxide monohydrate were added over 5 days. The mixture was concentrated and the residue dissolved in water. The solution was acidified by addition of aqueous hydrochloric acid (1N) and extracted with ethyl acetate. The combined organic extracts were dried over magnesium sulfate and concentrated to give a residue which was used without further purification in the following step. LC-MS showed the presence of 4-[5-(3,5-dichloro-phenyl)-4-ethylidene-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-2-methyl-benzoic acid: RT=2.20 min, m/z=442/444/446 (M−H+).

1. customthe reaction
2. concentrationThe mixture was concentrated
3. dissolutionthe residue dissolved in water
4. additionThe solution was acidified by addition of aqueous hydrochloric acid (1N)
5. extractionextracted with ethyl acetate
6. dry with materialThe combined organic extracts were dried over magnesium sulfate
7. concentrationconcentrated
8. customto give a residue which
9. customwas used without further purification in the following step