I-proline methyl ester 2133-40-6

L‑Proline methyl ester hydrochloride
CAS No.: 2133‑40‑6
Properties
Melting Point: 69‑71 °C(lit.)
Specific Rotation: -33 º (c=1, H₂O)
Boiling Point: 55 °C / 11 mmHg
Density: 1.1426 (rough estimate)
Refractive Index: -31.5 ° (C=1, H₂O)
Storage Condition: Inert atmosphere, 2‑8°C
Solubility: Soluble in chloroform; slightly soluble in methanol and water
Form: Crystalline powder, crystals and/or lumps
Color: White
Optical Rotation: [α]20/D 31°, c = 0.5 in H₂O
Sensitivity: Hygroscopic
BRN: 3596045
Stability: Hygroscopic
Main Application: Peptide synthesis
InChI: 1S/C6H11NO2.ClH/c1‑9‑6(8)5‑3‑2‑4‑7‑5;/h5,7H,2‑4H2,1H3;1H/t5‑;/m0./s1
InChIKey: HQEIPVHJHZTMDP‑JEDNCBNOSA‑N
SMILES: Cl[H].[H][C@]1(CCCN1)C(=O)OC
CAS Database Reference: 2133‑40‑6
Uses & Synthesis Method
Note: The synthetic procedure below is for academic literature reference only, not for commercial production guidance.
Uses
For biochemical research.
Used as biochemical reagent and pharmaceutical intermediate for laboratory synthesis.
Synthesis Method
L‑Proline methyl ester hydrochloride can be synthesized from methanol and L‑proline. General procedure from literature is described as follows:
(S)‑Proline (10.2 g, 88.6 mmol) reacts with thionyl chloride (11.6 g, 7.10 mL, 97.5 mmol) in refluxing methanol (60 mL) for 29 h to afford methyl (S)‑pyrrolidine‑2‑carboxylate. Upon reaction completion, excess solvent and thionyl chloride are removed under reduced pressure to give grey oily proline ester (15.9 g, quantitative yield).
Subsequently, 2‑fluoro‑1‑nitrobenzene (6.92 g, 5.18 mL, 49.0 mmol) reacts with the as‑prepared methyl (S)‑pyrrolidine‑2‑carboxylate (7.55 g, 45.6 mmol) following literature procedure. L‑Proline methyl ester hydrochloride is obtained as bright‑yellow crystals (12.0 g, quantitative yield). The product can be used for subsequent experiments without further purification.
References
[1] Heterocycles, 1986, vol. 24, # 4, p. 1045‑1060
[2] Bulletin des Societes Chimiques Belges, 1994, vol. 103, # 5‑6, p. 201‑206
[3] Journal of the Chemical Society‑Perkin Transactions 1, 1998, # 22, p. 3767‑3775
[4] European Journal of Organic Chemistry, 2002, # 19, p. 3304‑3314
[5] Tetrahedron, 2008, vol. 64, # 42, p. 9992‑9998