N-BENZYL-L-PROLINE

N-BENZYL-L-PROLINE Property

Melting point:

168-171°C

Boiling point:

343.1±35.0 °C(Predicted)

Density 

1.205

storage temp. 

Sealed in dry,2-8°C

solubility 

Acetone (Slightly), Dichloromethane (Slightly), Methanol (Slightly)

form 

Solid

pka

2.35±0.20(Predicted)

color 

White

optical activity

Consistent with structure

CAS DataBase Reference

31795-93-4(CAS DataBase Reference)

Safety

Hazard Codes 

Xi

Hazard Note 

Irritant

HS Code 

2933998090

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

N-BENZYL-L-PROLINE Chemical Properties,Usage,Production

Chemical Properties

White Solid

Uses

A reagent for the synthesis of optically pure a-amino-acids

Uses

A reagent for the synthesis of optically pure α-amino-acids.

Synthesis

L-proline (5.00 g, 43.44 mmol, 1.0 eq.) and potassium hydroxide (9.78 g, 174.3 mmol, 4 eq.) were dissolved in isopropanol (50 mL) and stirred at 40 °C until the solution was clarified. Subsequently, benzyl chloride (8.25 g, 7.50 mL, 65.2 mmol, 1.5 eq.) was added and the reaction continued to be stirred at 40 °C for 6 hours. Upon completion of the reaction, the reaction solution was neutralized with concentrated aqueous hydrochloric acid to pH 5-6. After neutralization, chloroform (30 mL) was added and the mixture was stirred overnight. The resulting precipitate was removed by filtration and the precipitate was washed with chloroform (30 mL). The organic phases were combined and the solvent was evaporated under vacuum. The resulting residue was treated with acetone (30 mL) to precipitate the crude product, which was filtered and washed with acetone to afford the white solid product (S)-1-benzylpyrrolidine-2-carboxylic acid (5.39 g, 26.26 mmol, 60% yield). The product was characterized as follows: Rf 0.09 (dichloromethane:methanol = 9:1); melting point 175 °C (literature value 167 °C); νmax(neat)/ cm-1 3041, 2992, 2969, 1634, 1450, 1375, 1311, 1190, 753, 704; 1H NMR (300 MHz, D2O) δ 7.53 (s, br, 5H, Ar-H), 4.40 (s, 2H, CH2Ph), 4.01 (dd, 1H, J = 6.7, 9.3 Hz, CHCO2H), 3.73-3.58 (m, 1H, CH2CH2aN), 3.38-3.21 (m, 1H, CH2CH2bN), 2.62-2.41 (m, 1H, CH2aCH), 2.27-1.89 (m, 3H, CH2bCH and CH2CH2N); 13C NMR (75 MHz, D2O) δ 173.54, 130.55, 130.05, 129.96, 129.25, 68.24, 58.30, 54.61, 28.79, 22.78; HRMS m/z ( ESI) 206.1215 ([M + H]+, calculated value 206.1165).

References

[1] Organic and biomolecular chemistry, 2003, vol. 1, # 17, p. 3010 - 3014
[2] Tetrahedron Asymmetry, 1998, vol. 9, # 23, p. 4249 - 4252
[3] Advanced Synthesis and Catalysis, 2014, vol. 356, # 10, p. 2203 - 2208
[4] Journal of Organic Chemistry, 2003, vol. 68, # 18, p. 7104 - 7107
[5] Journal of Organic Chemistry, 2011, vol. 76, # 6, p. 1513 - 1520