Triethylamine → (6-{6-[5-(2-Oxo-hexahydro-thieno[3,4-d]imidazol-4-yl)-pentanoylamino]-hexanoylamino}-hexyl)-carbamic Acid tert-Butyl Ester

Participants

Reaction Steps

6-[5-(2-Oxo-hexahydro-thieno[3,4-d]imidazol-4-yl)-pentanoylamino]-hexanoic acid 2,5-dioxo-pyrrolidin-1-yl ester (4; 0.39 g, 0.86 mmol) was completely dissolved in DMF (15 mL) with gentle warming. After cooling the solution to room temperature without reprecipitation, it was mixed with triethylamine (Et3N; 0.52 g, 5.15 mmol) followed by the addition of 5 (0.25 g, 1.14 mmol) in DMF (3 mL) dropwise while stirring. After overnight reaction at room temperature, the mixture was filtered, evaporated in vacuo, and loaded to a silica column for further purification. The products were separated by eluting with mobile phases of 5-20% MeOH in DCM to afford 6 (0.45 g; 93.8%) as a yellowish solid. 1H NMR (400 MHz) (CD3OD) δ: 4.53 (t, 1H, CHN), 4.34 (t, 1H, CHN), 3.25 (dd, 1H, CHS), 3.20 (t, 2H, CH2NH), 3.08 (t, 2H, CH2NH), 2.96 (d, 1H, CHHS), 2.73 (d, 1H, CHHS), 2.22 (t, 4H, CH2CO), 1.38-1.80 (m, 29H). 13C NMR (100.67 MHz) (DMSO) δ: 176.02, 175.97, 166.05, 158.50, 79.50, 63.39, 61.63, 57.01, 41.24, 41.04, 40.24, 36.99, 36.82, 30.90, 30.35, 30.13, 29.78, 29.49, 28.80, 27.56, 26.92, 26.74. HRMS (ESI) calculated for C27H49N5O5S, [M+Na]+ 578.3352 (calcd.), 578.3349 (found).

Provenance & Evidence