反应详情

5-Phenyl-4-(trifluoromethyl)isoxazole-3-carbonyl fluoride, Int-II-D (150 mg, 0.58 mmol) was dissolved in acetonitrile (10 mL) and DIEA (0.185 mL, 1.061 mmol) and ethyl 2-((3R)-1-(2-hydroxy-2-(4-((Z)—N′-hydroxycarbamimidoyl)phenyl)ethyl)piperidin-3-yl)acetate (185 mg, 0.530 mmol) were added. After one hr, TBAF in THF (0.530 mL, 0.530 mmol) was added and the reaction mixture was stirred overnight at room temperature. LCMS shows two new peaks. One is the desired mass and the other has a much higher mass which corresponds to double addition of acid fluoride. The reaction mixture was diluted with ethyl acetate and washed with saturated NaCl. The organic layer was dried with MgSO4, filtered, and concentrated. Solids were purified by a silica gel cartridge using an EtOAc/hexanes gradient to yield 72 mgs of ethyl 2-((3R)-1-(2-hydroxy-2-(4-(5-(5-phenyl-4-(trifluoromethyl)isoxazol-3-yl)-1,2,4-oxadiazol-3-yl)phenyl)ethyl)piperidin-3-yl)acetate. MS (m+1)=571. HPLC Peak RT=3.39 minutes.

1. washwashed with saturated NaCl
2. dry with materialThe organic layer was dried with MgSO4
3. filtrationfiltered
4. concentrationconcentrated
5. customSolids were purified by a silica gel cartridge