Dicyclohexylcarbodiimide → 3-(3-Pyridyl)-1-propyl (2s)-n-(tert-butyloxycarbonyl)-pyrrolidine-2-carboxylate

A mixture of N-(tert-butyloxycarbonyl)-(S)-proline (3.0 g; 13.9 mmol), 3-(3-Pyridyl)-1-propanol (2.90 g; 20.9 mmol), dicyclohexylcarbodiimide (4.59 g; 22.24 mmol), camphorsulfonic acid (1.08 g; 4.63 mmol), and 4-dimethylaminopyridine (0.60 g; 4.63 mmol) in dry methylene chloride (100 mL) was stirred overnight. The reaction mixture was diluted with methylene chloride (50 mL) and water (100 mL), and the layers were separated. The organic phase was washed with water (3×100 mL), dried over magnesium sulfate, and concentrated, and the crude residue was purified on a silica gel column eluting with ethyl acetate to obtain 4.60 g (95%) of the ester as a thick oil. 1H NMR (300 MHz, CDCl3): δ 1.45 (s, 9H); 1.70-2.05 (m, 5H); 2.32 (m, 1H); 2.71 (t, 2H); 3.50 (m, 2H); 4.15 (m, 2H); 4.18 (m, 1H); 7.24 (m, 1H); 7.51 (m, 1H); 8.48 (m, 2H).

1. customthe layers were separated
2. washThe organic phase was washed with water (3×100 mL)
3. dry with materialdried over magnesium sulfate
4. concentrationconcentrated
5. customthe crude residue was purified on a silica gel column
6. washeluting with ethyl acetate

ORD-Eintrag

ord-8ecdcc0565344e0d9e5594723727c290

Quelldatensatz

uspto-grants-2001_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06194440B1