反应详情

A solution of tert-butyl[2-(5-ethyloxycarbonyl-pentylsulfanyl)-benzoimidazol-1-yl]-acetate (Precursor E-01b, 44 mg, 0.11 mmol) in TFA/dichloromethane (1:1, 2 ml) is stirred at rt for 3 h. The solvents are removed under a stream of air. The solid residue is suspended in Et2O (2 ml) and sonicated. Filtration, rinsing with Et2O and drying under high vacuum yields the title compound (32 mg) as a white solid in 85% yield: tR=5.33 min (LC-1), ESI-MS (pos.): m/z 351.07 [M+H]+, ESI-MS (neg.): m/z 349.22 [M−H]+; 1H-NMR (CDCl3): δ (ppm) 1.25 (t, 3H CH3), 1.44 (s, 9H, tBu), 1.32-1.44 (m, 2H), 1.52-1.70 (m, 4H), 2.24 (t, 2H, CH2C═O), 3.24 (t, 2H, SCH2), 4.10 (q, 2H, OCH2), 4.15 (br. s, 1H, CO2H), 4.86 (s, 2H, CH2CO2), 7.24 (s, 3Harom), 7.63 (m, 1Harom).

1. customThe solvents are removed under a stream of air
2. customsonicated
3. filtrationFiltration
4. washrinsing with Et2O
5. customdrying under high vacuum