Triethylamine → N-[(2R)-2-(tert-butoxycarbonylamino)3-phenylpropyl]-N-[(2S)-2-(tert-butoxycarbonylamino)-3-phenylpropyl]-N-[9-fluorenylmethoxycarbonyl]amine

The product from Example 26B (1.28 g, 2.6 mmol) in tetrahydrofuran (11 mL) was treated with triethylamine (0.39 mL, 2.8 mmol) and 9-fluorenylmethyl chloroformate (0.72 g, 2.8 mmol) at ambient temperature. After stirring for 1 hour, the mixture was concentrated and the residue was dissolved in ethyl acetate (10 mL), wash with 10% NaHCO3 (2×10 mL), 10% citric acid (2×10 mL), brine (10 mL), dried over sodium sulfate, filtered and the filtrate was concentrated. The residue was purified by flash column chromatography on silica gel eluting with chloroform (1.68 g, 90%). 1H NMR (CDCl3) δ 7.82-6.94 (m, 18H), 4.93 (br s, 1H), 4.66-4.43 (m, 2H), 4.20 (t, 1H), 3.87-3.35 (m, 4H), 3.00-2.20 (m, 7H), 1.38-1.23 (m, 18H); MS (ESI+) m/z 706 (M+H)+.

1. concentrationthe mixture was concentrated
2. dissolutionthe residue was dissolved in ethyl acetate (10 mL)
3. washwash with 10% NaHCO3 (2×10 mL), 10% citric acid (2×10 mL), brine (10 mL)
4. dry with materialdried over sodium sulfate
5. filtrationfiltered
6. concentrationthe filtrate was concentrated
7. customThe residue was purified by flash column chromatography on silica gel eluting with chloroform (1.68 g, 90%)

ORD-Eintrag

ord-08a5ffa9e74a4246b64f1100a0ecba54

Quelldatensatz

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08524753B2