H-Glu(OtBu)-NH2·HCl

• CAS: 108607-02-9
• Catalog Number: ACM108607029
• Category: Main Products
• Molecular Weight: 238.70
• Molecular Formula: C9H18N2O3·HCl
• Synonyms: L-Glutamic acid g-tert-butyl ester a-amide, 108607-02-9, BP-13056
• IUPAC Name: tert-butyl (4S)-4,5-diamino-5-oxopentanoate;hydrochloride
• Canonical SMILES: CC(C)(C)OC(=O)CCC(C(=O)N)N.Cl
• InChI Key: NWLREMKEFHDCSV-RGMNGODLSA-N
• Exact Mass: 238.10800
• H-Bond Acceptor: 4
• H-Bond Donor: 3

Case Study

H-Glu(OtBu)-NH2·HCl Used in the Synthesis of Dendritic Polypeptides for Drug Delivery

Alsehli M, et al. MRS Online Proceedings Library (OPL), 2016, 1819.

Amine-terminated poly(γ-L-glutamic acid benzyl ester) (PBG) chains can be used to synthesize dendritic graft (arborescent) peptides. In the synthesis route, H-Glu(OtBu)-NH2·HCl is an important synthetic raw material for chain end functionalized G1PBG substrate. Subsequently, the obtained dendritic PBG substrate was grafted with poly(ethylene oxide) (PEO) fragments to further construct water-dispersible monomolecular micelles that could be used as doxorubicin delivery vehicles.
Synthesis Procedures of G1PBG-eg-PEO arborescent copolymer
· A linear polymer serving as side chains was obtained using Glu-NCA (16 mmol) in dry DMF and H-Glu(OtBu)-OtBu·HCl (0.72 mmol) at 40 ˚C for 7 days, adding TEA (0.09 mL, 0.9 mmol), and stirring for 20 min at 25 ˚C.
· The polymer was then recovered and coupled with the partially deprotected G0 arborescent PBG substrate before purification by SEC. The tert-butyl ester protecting groups at the chain ends were selectively removed by dissolving the G1PBG substrate in trifluoroacetic acid.
· The chain end-functionalized G1PBG substrate (0.15 mmol) and linear PEO with a terminal primary amine group (0.15 mmol) were dissolved in 4 mL of dry DMSO. DIC (0.75 mmol), HOBt (0.75 mmol) and TEA (0.75 mmol) were then added. The reaction was allowed to proceed for 64 h at room temperature.

H-Glu(OtBu)-NH2·HCl for the Synthesis of Modified Poly(c-benzyl L-glutamate)

Whitton G, et al. Journal of Polymer Science Part A: Polymer Chemistry, 2016, 54(9), 1197-1209.

A synthetic strategy for unimolecular micelles based on G1-G3 dendritic poly(c-L-benzyl glutamate) (PBG) cores has been developed. The coupling sites randomly distributed on the PBG matrix or located at the ends of the dendritic chains can react with poly(ethylene oxide) (PEO) segments, polyglycidyl acetal (PGlyAc) or poly(L-tert-butyl glutamate) (PtBuGlu). In this synthetic strategy, the tert-butyl diester of glutamic acid [H-Glu(OtBu)-NH2·HCl] plays an important role in initiating the polymerization of Bz-Glu-NCA.
Synthesis Procedures of Glu(OtBu)2-PBG
· To synthesize (tBuO)2-PBG, the polymerization of Bz-Glu-NCA was initiated using H-Glu(OtBu)-NH2·HCl to generate linear PBG side chains for the final grafting cycle in the arborescent PBG core synthesis.
Bz-Glu-NCA (5.0 g, 19.0 mmol) was dissolved in dry DMF (10 mL) with stirring, and the temperature was raised to 40 °C.
· A solution of H-Glu(OtBu)-OtBuHCl (0.243 g, 0.82 mmol, in 2 mL of dry DMF) was then added to achieve a target Xn of 23.
· After 7 days, the reaction mixture was brought to room temperature and triethylamine (TEA; EMD, 0.1 mL, 1 mmol) was introduced. The polymer was subsequently precipitated in methanol, filtered with suction, and dried under vacuum after 5 minutes.