反应详情

H-Lys(Boc)-Pro-Pro-Arg(Pmc)-t-Bu (3.55 g, 3.86 m mmol) was added to a solution of the activated acid prepared from Fmoc-Thr(t-Bu)-OH (1.6 g, 4 mmol) and HATU (1.9 g, 5 mmol) and DIEA (1.29 g, 10 mmol) in dry CH2Cl2 (25 mL) and stirred for 20 h at RT. The reaction mixture was then diluted with ethyl acetate (200 mL) and washed with saturated sodium carbonate (2×200 mL), water (2×200 mL) and dried (sodium sulfate). The solution was filtered and the solvents were removed under reduced pressure to leave behind a paste. The paste was chromatographed over flash silica gel (400 g). Elution with 2% methanol in chloroform furnished the product as a colorless foam. Yield: 3.5 g (70%). m.p. 135-138° C. MS m/z 1298.2 [M+H].

1. washwashed with saturated sodium carbonate (2×200 mL), water (2×200 mL)
2. dry with materialdried (sodium sulfate)
3. filtrationThe solution was filtered
4. customthe solvents were removed under reduced pressure
5. customto leave behind a paste
6. customThe paste was chromatographed over flash silica gel (400 g)
7. washElution with 2% methanol in chloroform