Carbamate → 2-(4-{2-[2-(tert-Butyl-dimethyl-silanyloxymethyl)-pyrrolidine-1-carbonyl]-4,5-dimethoxy-phenylcarbamoyloxymethyl}-phenoxycarbonylamino)-pentanedioic acid diallyl ester

Beteiligte Stoffe

Reaktionsschritte

A solution of the carbamate progroup 42 (1.48 g, 3.92 mmol) and triethylamine (0.45 g, 0.6 mL, 4.3 mmol) in anhydrous CH2Cl2 (30 mL) was added to a solution of the isocyanate 7 prepared from the amine 5 (1.54 g, 3.92 mmol), triphosgene (0.42 g, 1.4 mmol) and triethylamine (0.535 g, 0.74 mL, 5.3 mmol) in anhydrous toluene (50 mL). The reaction was complete in 4 h. The product was obtained (flash column chromatography 40% EtOAc/60% n-hexane) as a colourless oil (1.76 g, 56). 1H NMR (CDCl3) δ 9.22 (bs, 1H), 7.87 (s, 1H), 7.40 (d, J=10 Hz, 2H), 7.13 (d, J=7.5 Hz, 2H), 6.83 (s, 1H), 5.93 (m, 2H), 5.74 (d, J=8.3 Hz, 1H), 5.30 (m, 4H), 5.17 (d, J=12.5 Hz, 1H), 5.15 (d, J=12.5 Hz, 1H) 4.68 (d, J=5 Hz, 2H) 4.61 (d, J=5 Hz, 1H), 4.48 (m, 1H), 4.35 (m, 1H), 3.95 (s, 3H), 3.82 (s, 3H), 3.65 (m, 1H), 3.50 (m, 2H), 2.55 (m, 2H), 2.30 (m, 1H), 2.1 (m, 3H), 1.95 (m, 1H), 1.8 (m, 1H), 0.9 (s, 9H), 0.04 (s, 6H). IR (neat) 3338, 2953, 2857, 1735, 1615, 1597, 1522 cm−1.

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