反应详情

To a solution of 3-(2-ethyl-4-{5-[2-(isopropyl-methyl-amino)-6-methyl-pyridin-4-yl]-[1,2,4]oxadiazol-3-yl}-6-methyl-phenyl)-propionic acid (43 mg, 0.101 mmol) and DIPEA (40 mg, 0.304 mmol) in DMF (3 mL) is added PyBOP (58 mg, 0.111 mmol) at 0° C. The mixture is stirred for 15 min at 0° C. before β-alanine tert.-butyl ester (20 mg, 0.111 mmol) is added and stirring is continued for 1 h at 0° C. The reaction is quenched with 2 mL water, and the mixture is diluted in sat. aq. NaHCO3-solution, and extracted three times with diethyl ether. The combined org. extracts are dried over MgSO4, filtered and dried to give crude 3-[3-(2-ethyl-4-{5-[2-(isopropyl-methyl-amino)-6-methyl-pyridin-4-yl]-[1,2,4]oxadiazol-3-yl}-6-methyl-phenyl)-propionylamino]-propionic acid tert-butyl ester (46 mg). This material is dissolved in 4 N HCl in dioxane (5 mL) and the mixture is stirred at rt for 18 h. The solvent is evaporated and the crude product is purified on prep. TLC plates with DCM containing 18% of 7 N NH3 in methanol to give 3-[3-(2-ethyl-4-{5-[2-(isopropyl-methyl-amino)-6-methyl-pyridin-4-yl]-[1,2,4]oxadiazol-3-yl}-6-methyl-phenyl)-propionylamino]-propionic acid (37 mg) as a yellow solid; LC-MS: tR=0.86 min; [M+1]+=494.24.

1. additionis added
2. customThe reaction is quenched with 2 mL water
3. additionthe mixture is diluted in sat. aq. NaHCO3-solution
4. extractionextracted three times with diethyl ether
5. dry with materialextracts are dried over MgSO4
6. filtrationfiltered
7. customdried