Ethyl Acetate → Methyl N-(ethoxycarbonyl)-O-(3'-{[(propylamino)carbonyl]amino}-1,1'-biphenyl-3-yl)-L-serinate

Participants

Reaction Conditions

Reaction Steps

The compound of Example 6 (256.0 mg, 0.63 mmol, 1 equiv) was suspended in THF (3 mL) and cooled to 0° C. Ethyl chloroformiate (88.5 mg, 0.82 mmol, 1.3 equiv) was added dropwise followed by N,N diisopropylethylamine (234.3 mg, 1.88 mmol, 3 equiv). The reaction mixture was allowed to warm to room temperature and stirred for one hour. It was worked up by addition of sat. aqueous NH4Cl soln. and ethyl acetate. The phases were separated and the organic layer was dried over NaSO4. After filtration and evaporation of the solvents the crude product was purified by chromatography (SiO2 CH/EtOAc 90:10). Yield 210.0 mg, 75.4% of a white solid. 1H NMR (CDCl3, 300 MHz) δ 7.50 (s, 1H); 7.39-7.25 (m, 3H); 7.21 (d, 1H), 7.12 (d, 1H); 7.05 (s, 1H); 6.90 (brs, 1H); 6.81 (d, 1H); 5.80 (d, 1H); 5.10 (m, 1H); 4.75-4.65 (m, 1H); 4.42 (dd, 1H); 4.25 (dd, 1H); 4.20-4.10 (m, 2H); 3.79 (s, 3H); 3.20 (dd, 2H); 1.52 (sext, 2H); 1.22 (t, 3H); 0.95 (t, 3H). MS (DCI/NH3) 461 (M+NH4), 444 (M+H).

Provenance & Evidence