Pyridine → HCID 131726471, compound

Participants

Reaction Steps

A solution of 70 mg (85 μmol) of compound 30, pyridine (17 μl, 2.5 equiv) and 4-nitrophenylchloroformate (34 mg, 2.0 equiv) was stirred under an Argon atmosphere at 0° C. for two hours and for 24 hours at room temperature. The solution was evaporated in vacuo and the residual product was dissolved in chloroform. After washing the organic layer with brine and 0.5 N potassium bisulfate, the organic layer was dried over anhydrous sodium sulfate and concentrated to dryness. The resulting crude product was subjected to column chromatography (SiO2—CHCl3/MeOH 20/1) to obtain 54 mg (64%) of 31 as a pale yellow solid. 1H-NMR (300 MHz, CDCl3/CD3OD): δ 0.90–2.10 (m, 9H, CH3-Ala and 3 CH2-Lys), 2.90–3.10 (m, 4H, N—CH2-Lys and CH2-Trp), 3.27 (bd, 1H, benzylic), 4.35–4.78 (m, 6H, 2Hα and Aloc), 4.90–5.52 (m, 4H, Aloc), 5.13 (s, 2H, benzylic-spacer), 5.60 (m, 1H, Aloc), 5.94 (m, 1H, Aloc), 7.10–7.46 (m, 15H, aromatic), 8.36 (d, 2H, aromatic-PNP) ppm; MS (FAB) m/e 991 (M+H)+, 1013 (M+Na)+; C50H54N54N8O14.¾H2O) calculated C 59.78%; H, 5.57 %; N, 11.15%; measured C, 60.12%; H, 5.89%; N, 10.76%.

Provenance & Evidence