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

Participants

Reaction Steps

Methyl O-(3′-amino-1,1′-biphenyl-3-yl)-N-triphenylmethyl-L-serinate (Example 2) (250.0 mg, 0.47 mmol, 1 equiv) was dissolved in toluene (5 mL) and treated at rt with n-propyl isocyanate (402.5 mg, 4.73 mmol, 10 equiv) and DABCO (1,4-diazabicyclo[2,2,2]octane) (5.3 mg, 0.05 mmol, 0.1 equiv). The reaction mixture was stirred at rt for 14 h and then partitioned between toluene and sat. aqueous NH4Cl solution. The organic layer was separated and dried over NaSO4 and the solvents were removed in vacuuo. The crude product was titurated with petroleum ether to give a yellow solid. Yield 210.0 mg, 72.4%. 1H NMR (CDCl3, 200 MHz) δ 7.65-7.50 (m, 9H); 7.40-7.15 (m, 12H); 6.95 (d, 2H); 5.19-4.98 (m, 1H); 4.25 (dd, 1H); 4.03 (dd, 1H); 3.38-3.02 (m, 4H); 2.88 (d, 1H); 1.65-1.45 (m, 2H); 0.90 (t, 3H). MS (EI) 614 (M+H), 243 (CPh3).

Provenance & Evidence