反应详情

To a solution of 2-(1-ethyl-propyl)-6-methoxy-isonicotinic acid (436 mg, 1.95 mmol) and DIPEA (759 mg, 5.86 mmol) in DMF (30 mL), TBTU (627 mg, 1.95 mmol) is added. The mixture is stirred at rt for 15 min before 3-ethyl-4,N-dihydroxy-5-methyl-benzamidine (379 mg, 1.95 mmol) is added. Stirring is continued at rt for 2 h. The mixture is diluted with DCM (100 mL) and washed three times with sat. aq. NaHCO3 solution. The org. extract is dried over MgSO4, filtered and concentrated. The residue is dissolved in dioxane (20 mL) and the mixture is stirred at 100° C. for 18 h. The mixture is concentrated and the crude product is purified by prep. HPLC to give 2-ethyl-4-{5-[2-(1-ethyl-propyl)-6-methoxy-pyridin-4-yl]-[1,2,4]oxadiazol-3-yl}-6-methyl-phenol (355 mg) as a beige solid; LC-MS: tR=1.20 min, [M+H]+=382.04; 1H NMR (CDCl3): δ0.84 (t, J=7.3 Hz, 6H), 1.34 (t, J=7.5 Hz, 3H), 1.68-1.89 (m, 4H), 2.36 (s, 3H), 2.57-2.65 (m, 1H), 2.74 (q, J=7.8 Hz, 2H), 4.02 (s, 3H), 5.00 (s br, 1H), 7.33 (s, 1H), 7.45 (s, 1H), 7.85 (s, 2H).

1. additionis added
2. washwashed three times with sat. aq. NaHCO3 solution
3. extractionextract
4. dry with materialis dried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated
7. dissolutionThe residue is dissolved in dioxane (20 mL)
8. stirringthe mixture is stirred at 100° C. for 18 h
9. concentrationThe mixture is concentrated
10. customthe crude product is purified by prep