1-Hydroxybenzotriazole → trans-4-(3-Biphenyloxy) N-tert-butoxycarbonyl-L-proline 2-(N-tert-butoxycarbonylamino)ethylamide

Participants

Reaction Steps

Triethylamine (56 μL), 1-hydroxybenzotriazole (25 mg), and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (78 mg) were added to a solution of trans-4-(3-biphenyloxy)-N-tert-butoxycarbonyl-L-proline (B), (141 mg) and tert-butyl N-(2-aminoethyl)carbamate (65 mg) in dichloromethane (3 mL). After stirring at room temperature overnight, the reaction mixture was diluted with chloroform and washed with saturated sodium hydrogen carbonate and brine. The organic layer was dried over anhydrous sodium sulfate and evaporated in vacuo. The residue was purified by silica gel column chromatography chloroform:methanol=100:1, v/v to give the titled compound (175 mg) as a colorless foam: 1H NMR (400 MHz, CDCl3) δ 1.45 (s, 9H), 2.37 (m, 1H), 2.59 (m, 1H), 3.28 (m, 1H), 3.29 (s, 2H), 3.40 (m, 1H), 3.73 (m, 2H), 4.41 (m, 1H), 5.01 (m, 1H), 5.18 (m, 1H), 6.86 (m, 2H), 7.08 (s, 1H), 7.20 (d, J=7.3 Hz, 1H), 7.35 (t, J=7.3 E4z, 2H), 7.43 (t, J=7.3 Hz, 2H), and 7.56 (d, J=7.3 Hz,2H).

Provenance & Evidence