Benzyl chloroformate → Benzyl 3-hydroxypyrrolidine-1-carboxylate
Reaction equation
[OH:1][CH:2]1[CH2:6][CH2:5][NH:4][CH2:3]1.Cl[C:8]([O:10][CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:9]>[OH-].[K+]>[OH:1][CH:2]1[CH2:6][CH2:5][N:4]([C:8]([O:10][CH2:11][C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)=[O:9])[CH2:3]1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A solution of 4.29 g (48.9 mmol) of 3-hydroxypyrrolidine in 30 mL of 2N potassium hydroxide was cooled to 0° C. and 10.2 mL of benzyl chloroformate were added with stirring. The reaction was stirred for four hours at 0° C. and then extracted with ethyl acetate (3×100 mL). The extracts were combined, washed with brine, dried over sodium sulfate, filtered, and concentrated in vacua. The residue was chromatographed on silica gel with 70/30 hexanes/ethyl acetate. The correct fractions were combined and concentrated in vacuo to give 8.87 g (81%) of benzyl 3-hydroxypyrrolidine-1-carboxylate as a viscous clear oil. Rf=0.11 in 50/50 hexanes/ethyl acetate Mass Spectrum (FD+): M+221; IR (CHCl3, cm-1): 913, 977, 993, 1100, 1117, 1175, 1236, 1360, 1427, 1454, 1498, 1694, 2884, 2954, 3013, 3020, 3436 (broad), 3610; UV (C2H5OH) λmax =205 (ε=9112), 264 (ε=142); 1H NMR (300 MHz, CDC13) δ: 1.91-2.05 (m-, 2H); 3.00 (broad s, 1H); 3.39-3.61 (m, 4H); 4.41 (s, 1H); 5.12 (s, 2H); 7.30-7.43 (m, 5H).
Workup
- stirringThe reaction was stirred for four hours at 0° C.
- extractionextracted with ethyl acetate (3×100 mL)
- washwashed with brine
- dry with materialdried over sodium sulfate
- filtrationfiltered
- concentrationconcentrated in vacua
- customThe residue was chromatographed on silica gel with 70/30 hexanes/ethyl acetate
- concentrationconcentrated in vacuo
Sources & evidence
- ORD record
- ord-72e52757431f4ee8b977ae9481e3516a
- Source dataset
- uspto-grants-1998_07
- Patent number
- US05786358
Reaction notes
Loading…