Diisopropylethylamine → {2-[3-(2-Ethyl-4-{5-[2-(isopropyl-methyl-amino)-6-methyl-pyridin-4-yl]-[1,2,4]oxadiazol-3-yl}-6-methyl-phenyl)-propionylamino]-ethyl}-carbamic acid tert-butyl ester

Participants

Reaction Steps

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 (41 mg, 0.097 mmol) and DIPEA (38 mg, 0.291 mmol) in DMF (3 mL) is added PyBOP (56 mg, 0.107 mmol) at 0° C. The mixture is stirred for 15 min at 0° C. before N-BOC-ethylenediamine (17 mg, 0.107 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 {2-[3-(2-ethyl-4-{5-[2-(isopropyl-methyl-amino)-6-methyl-pyridin-4-yl]-[1,2,4]oxadiazol-3-yl}-6-methyl-phenyl)-propionylamino]-ethyl}-carbamic acid tert-butyl ester (44 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 6% of 7 N NH3 in methanol to give N-(2-amino-ethyl)-3-(2-ethyl-4-{5-[2-(isopropyl-methyl-amino)-6-methyl-pyridin-4-yl]-[1,2,4]oxadiazol-3-yl}-6-methyl-phenyl)-propionamide (23 mg) as a yellow solid; LC-MS: tR=0.72 min; [M+1]+=465.32.

Provenance & Evidence