DL-Proline Chemical Properties

Melting point:

208 °C (dec.) (lit.)

Boiling point:

215.41°C (rough estimate)

Density 

1.1808 (rough estimate)

refractive index 

1.4538 (estimate)

storage temp. 

Keep in dark place,Inert atmosphere,Room temperature

solubility 

Methanol, Water

pka

2.35±0.20(Predicted)

form 

Crystalline Powder

color 

White to off-white

Water Solubility 

SOLUBLE

Merck 

14,7780

BRN 

80809

Major Application

peptide synthesis

Cosmetics Ingredients Functions

SKIN CONDITIONING
HAIR CONDITIONING

InChI

1S/C5H9NO2/c7-5(8)4-2-1-3-6-4/h4,6H,1-3H2,(H,7,8)

InChIKey

ONIBWKKTOPOVIA-UHFFFAOYSA-N

SMILES

OC(=O)C1CCCN1

CAS DataBase Reference

609-36-9(CAS DataBase Reference)

NIST Chemistry Reference

DL-Proline(609-36-9)

EPA Substance Registry System

Proline (609-36-9)

Safety Information

Hazard Codes 

Xn

Risk Statements 

22-36/37/38

Safety Statements 

22-24/25-36/37/39-26

WGK Germany 

3

F 

3-10

TSCA 

TSCA listed

HS Code 

29339990

Storage Class

11 - Combustible Solids

MSDS

• Language:English Provider:DL-Proline
• Language:English Provider:ACROS
• Language:English Provider:SigmaAldrich
• Language:English Provider:ALFA

DL-Proline Usage And Synthesis

Chemical Properties

white to off-white crystalline powder

Uses

DL-Proline is the racemic mixture of both L-Proline (P755995) and D-Proline (P755990).

Definition

ChEBI: An alpha-amino acid that is pyrrolidine bearing a carboxy substituent at position 2.

reaction suitability

reaction type: solution phase peptide synthesis

Synthesis

Input 100g of glacial acetic acid into the reaction kettle, and then input 100g of L-proline under stirring to obtain the reaction solution. After the reaction solution was stirred and warmed to 70-75??C, it was kept warm and stirred for 3h to make the L-proline fully racemic, which in turn made the reaction solution have a spin of 0, and at this time, the reaction solution was reddish-brown in color.

The reaction solution with spin 0 was cooled to 30 ??, and then moved to the distillation kettle for distillation under reduced pressure, the temperature of distillation was at 55-60 ??, the vapor pressure was 0.1MPa, and the distillation was continued for 30min after distillation until there was no liquid effluent, and then the residue of distillation was concentrated to 10% of the original volume to obtain the viscous concentrate A.

The concentrate A was mixed with 120g of isopropanol, stirred until the crystals precipitated completely, then cooled down to 15??C, centrifuged to remove excess liquid, and the crystals were rinsed with isopropanol to obtain the crude product.

Mix 90g of crude product, 5g of activated carbon, 185g of water and stir to raise the temperature to 70??, keep warm and stir for 30min to make the crude product dissolve completely, then filter to remove the activated carbon. The residue without activated carbon after filtration was concentrated to 20% of the original volume to obtain a viscous concentrate B.

The concentrate B was mixed with 285g of isopropanol, stirred until the crystals precipitated completely, then cooled to 15??C, centrifuged to remove the excess liquid, rinsed the crystals with isopropanol, and after rinsing, the crystals were dried at 80??C for 12h to obtain the sample of DL-proline.

DL-Proline(609-36-9)Related Product Information

• D-Proline
• L-PROLINE-(4-3H(N))
• Ethyl 2-(Chlorosulfonyl)acetate
• L-Proline
• Pyrrolidine
• GLYCYL-L-PROLINE
• Ascoric Acid
• cis-4-Hydroxy-L-proline
• BOC-L-Proline
• N-(2,4-DINITROPHENYL)-L-PROLINE
• Cyclopentene oxide
• Fmoc-Pro-OH
• Methyl L-prolinate hydrochloride
• Ethyl D-(-)-pyroglutamate
• BOC-HYP(BZL)-OH
• cis-4-Hydroxy-D-proline
• N-Methyl-L-proline
• N-Cbz-Hydroxy-L-proline