反应详情

To a solution of 2-cyclopentyl-N-hydroxy-6-methoxy-isonicotinamidine (870 mg, 3.70 mmol), 4-benzyloxy-3-ethyl-5-methyl-benzoic acid (1.00 g, 3.70 mmol) and DIPEA (1.44 g, 11.1 mmol) in DCM (30 mL), TBTU (1.43 g, 4.44 mmol) is added. The mixture is stirred at rt for 1 h before diluted with EA (150 mL) and water (50 mL). The org. phase is separated, washed with sat. aq. NaHCO3 solution (50 mL) followed by brine (50 mL), dried over MgSO4, filtered and concentrated. The remaining pale brown oil is dissolved in dioxane (40 mL) and then stirred at 115° C. for 48 h. The solvent is evaporated and the crude product is purified by CC on silica gel eluting with heptane:EA 1:9 to give 4-[5-(4-benzyloxy-3-ethyl-5-methyl-phenyl)-[1,2,4]oxadiazol-3-yl]-2-cyclopentyl-6-methoxy-pyridine (1040 mg) as a pale yellow oil; LC-MS**: tR=1.11 min, [M+H]+=470.26.

1. customphase is separated
2. washwashed with sat. aq. NaHCO3 solution (50 mL)
3. dry with materialdried over MgSO4
4. filtrationfiltered
5. concentrationconcentrated
6. dissolutionThe remaining pale brown oil is dissolved in dioxane (40 mL)
7. stirringstirred at 115° C. for 48 h
8. customThe solvent is evaporated
9. customthe crude product is purified by CC on silica gel eluting with heptane:EA 1:9