L-Valine benzyl ester 4-toluenesulfonate Chemical Properties

Melting point:

160-162 °C

alpha 

-3.7 º (c=3.2% in methanol)

Boiling point:

160-162°C

Flash point:

160-162°C

storage temp. 

Inert atmosphere,Store in freezer, under -20°C

solubility 

Soluble in Chloroform,Dichloromethane,Ethyl Acetate,DMSO,Acetone,etc.

form 

Powder

Appearance

White to off-white Solid

optical activity

[α]20/D 3.7±0.3°, c = 3.2% in methanol

BRN 

3643436

InChI

InChI=1/C12H17NO2.C7H8O3S/c1-9(2)11(13)12(14)15-8-10-6-4-3-5-7-10;1-6-2-4-7(5-3-6)11(8,9)10/h3-7,9,11H,8,13H2,1-2H3;2-5H,1H3,(H,8,9,10)/t11-;/s3

InChIKey

QWUQVUDPBXFOKF-XAAIUDFWNA-N

SMILES

C1(=CC=CC=C1)COC([C@@H](N)C(C)C)=O.C1(S(=O)(=O)O)C=CC(C)=CC=1 |&1:9,r|

CAS DataBase Reference

16652-76-9(CAS DataBase Reference)

Safety Information

Safety Statements 

22-24/25

WGK Germany 

3

MSDS

• Language:English Provider:SigmaAldrich
• Language:English Provider:ALFA

L-Valine benzyl ester 4-toluenesulfonate Usage And Synthesis

Chemical Properties

Crystalline

Uses

Val-OBzl TosOH is a L-Valine derivative useful as intermediate for the preparation of peptides.

reaction suitability

reaction type: solution phase peptide synthesis

Synthesis

GENERAL STEPS: The esterification reaction was carried out on L-amino acids, except phenylglycine, where the D-enantiomer was used. A mixture of L-valine (0.05 mol), 4-methylbenzenesulfonic acid (0.06 mol), benzyl alcohol (0.25 mol), and cyclohexane (30 mL) was refluxed for 4 hours using a Dean-Stark apparatus to separate the water with which it formed an azeotrope. After cooling the reaction mixture to room temperature, ethyl acetate (80 mL) was added. After stirring for 1 hour, the precipitate was collected by filtration and dried to give L-valyl benzyl ester p-toluenesulfonate as a white solid. Following this method, amino acids 1-6 were converted to the corresponding benzyl p-toluenesulfonate 1a-6a. benzylation of compound 7 was carried out in the same manner but in the presence of more 4-methylbenzenesulfonic acid (0.11 mol) to give di-p-toluenesulfonate 7a as a white solid. The p-toluenesulfonate 8a separated as an oil at the end of the reaction; instead of adding ethyl acetate, the supernatant was removed, the oil phase was washed with cyclohexane, and poured into an aqueous solution of dichloromethane/Na2CO3. After separation of the aqueous layer, the dichloromethane was evaporated and the residue was treated with methanol hydrochloride to give the corresponding hydrochloride salt as a white solid. The benzylation of compound 9 was prolonged overnight and at the end of the reaction, 9a separated as an oil, which was poured into dichloromethane/water. After removal of the organic layer, the aqueous phase was alkalized with NaHCO3 and extracted with ethyl acetate. The organic extract was concentrated to a small volume and a slight excess of 4-methylbenzenesulfonic acid was added to precipitate 9a as a white crystalline solid.

References

[1] Tetrahedron Letters, 2008, vol. 49, # 49, p. 6962 - 6964
[2] Journal of the Indian Chemical Society, 2001, vol. 78, # 3, p. 137 - 141
[3] Amino Acids, 2017, vol. 49, # 5, p. 965 - 974
[4] Chirality, 2012, vol. 24, # 2, p. 188 - 192
[5] European Journal of Medicinal Chemistry, 2018, vol. 157, p. 962 - 977

L-Valine benzyl ester 4-toluenesulfonate(16652-76-9)Related Product Information

• Benzyl benzoate
• Benzyl alcohol
• Benzyl chloride
• SODIUM P-TOLUENESULFONATE
• Methyl acrylate
• Tris(trimethylsilyl)phosphate
• L-Valine
• p-Toluenesulfonic acid
• Sodium xylenesulfonate
• Benzyl nicotinate
• Sorafenib tosylate
• Sodium p-toluenesulfonate
• ALPHA-METHYL-L-TRYPTOPHAN
• H-VAL-PNA HCL
• L-Valine benzyl ester hydrochloride
• H-VAL-ILE-OH
• H-VAL-ALA-OH
• ALPHA-METHYL-L-VALINE HYDROCHLORIDE