Fmoc-Asp(OtBu)-OH Chemical Properties

Melting point:

148-150 °C (dec.)

Boiling point:

530.45°C (rough estimate)

alpha 

-25 º (c=1,DMF 24 ºC)

Density 

1.2498 (rough estimate)

refractive index 

-25 ° (C=1, DMF)

storage temp. 

2-8°C

solubility 

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

pka

3.57±0.23(Predicted)

form 

powder to crystal

color 

White to Almost white

optical activity

[α]20/D 24±2°, c = 1% in DMF

Water Solubility 

Slightly soluble in water.

BRN 

3635671

InChIKey

FODJWPHPWBKDON-IBGZPJMESA-N

CAS DataBase Reference

71989-14-5(CAS DataBase Reference)

Safety Information

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

24/25-36/37/39-27-26

WGK Germany 

3

HazardClass 

IRRITANT

HS Code 

29242990

MSDS

• Language:English Provider:FMOC-L-Aspartic acid beta-tert-butyl ester
• Language:English Provider:ACROS
• Language:English Provider:SigmaAldrich

Fmoc-Asp(OtBu)-OH Usage And Synthesis

Chemical Properties

Fmoc-Asp(OtBu)-OH is a protected form of L-aspartic acid. It is a white to light yellow crystal powder. The molecule contains ester groups and amino groups, making it prone to polymerization and unstable over time. Therefore, it is not recommended to store it for extended periods.

Uses

L-Aspartic acid is a nonessential amino acid that is used to biosynthesize other amino acids within the human body.

Preparation

Fmoc-Asp(OtBu)-OH was prepared by substitution reaction with 9-fluorenylmethyl chloroformate from L-aspartic acid 4-tert-butyl ester.

General Description

Fmoc-Asp(OtBu)-OH is a white to off-white solid, it can be used for peptide synthesis.

reaction suitability

reaction type: Fmoc solid-phase peptide synthesis

Synthesis

The general procedure for the synthesis of Fmoc-L-aspartic acid β-tert-butyl ester from the compound (CAS:144120-52-5) was as follows: firstly, PdEnCat 30 (Aldrich; loading 0.4 mmol/g, use 0.05 eq.) was suspended in THF-H2O (9:1 v/v, total 5 mL) and treated with argon bubbling for 10 min for deoxygenation. Subsequently, DCHT (0.15 eq.) and the corresponding ester 1 (1.0 eq., 70 mg) were added under positive pressure. Finally, PhSiH3 (2.0 eq.) was injected and the reaction mixture was allowed to react at room temperature for 2 h. The reaction was carried out under low pressure. After completion of the reaction, the mixture was filtered through Celite and the filtrate was concentrated under reduced pressure. The residual solid was dissolved with EtOAc (20 mL) and washed sequentially with H2O (3 x 10 mL) and brine (3 x 10 mL). The organic layer was dried over MgSO4 and concentrated in vacuum. Purification was carried out by solid phase extraction (using C18 reversed-phase chromatography with H2O/MeOH as eluent) to obtain pure carboxylic acid 2 (see Table 1 for yields). The purity of the products was confirmed analytically by HPLC, 1H NMR and 13C NMR. All the carboxylic acids were commercially available. The 1H and 13C NMR spectra of the synthesized compounds were in agreement with those of commercial samples.

References

[1] Synlett, 2014, vol. 25, # 16, p. 2319 - 2322

Fmoc-Asp(OtBu)-OH(71989-14-5)Related Product Information

• L-Aspartic acid
• Fmoc-L-aspartic acid
• Fmoc-Aib-OH
• Tris(trimethylsilyl)phosphate
• Butyl acetate
• L-Fmoc-Aspartic acid alpha-tert-butyl ester
• 9-Fluorenylmethyl chloroformate
• L-ASPARTIC ACID
• FMOC-ASN(TRT)-OPFP
• 2-Butoxyethanol
• Buprofezin
• Poly-L-aspartic acid
• Butyl acrylate
• Fmoc-OSu
• FMOC-S-trityl-L-cysteine
• Fmoc-Trp(Boc)-OH
• Nalpha-Fmoc-Ndelta-trityl-L-glutamine
• Fmoc-Tyr(tBu)-OH