ChemicalBook CAS DataBase List 5-Benzyl L-glutamate N-carboxyanhydride

5-Benzyl L-glutamate N-carboxyanhydride synthesis

10synthesis methods

Product Name:5-Benzyl L-glutamate N-carboxyanhydride
CAS Number:3190-71-4
Molecular formula:C13H13NO5
Molecular Weight:263.25

5-Benzyl L-glutamate N-carboxyanhydride (γ-benzyl-L-glutamate-N-carboxyanhydride)was synthesized by a reaction between γ-benzyl-L-glutamate (BLG) and triphosgene. Briefly, 14 g BLG was dissolved in 200 mL anhydrous THF in reaction vessel with condensing reflux unit at stirring state. Then the solution was heated to 50 °C, and 20 g triphosgene was added. The reaction continued until the solution turned from cloudy to clear. The reaction was cooled to room temperature, and N2 was concurrently inlet into the reaction system until the liquid volume did not decrease any more. The solution was precipitated by n-hexane. After being purified by EA/n-hexane and dried in a vacuum oven, 5-Benzyl L-glutamate N-carboxyanhydride was obtained and characterized by 1H nuclear magnetic resonance (1H NMR, Bruker, AV300) using CDCl3 as a solvent[1].

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Yield:3190-71-4 95.4%

Reaction Conditions:

in tetrahydrofuran;toluene at 50; for 1 h;

Steps:

8 L-benzylglutamate NCA

Example 8
L-benzylglutamate NCA
Vacuum-dried H-Glu(OBn)-OH (71.2 g, 300.0 mmol) was suspended in 900 mL of anhydrous THF. Phosgene (20% in toluene) (210 mL, 420 mmol) was added to the amino acid suspension at room temperature and after ten minutes, the mixture was heated to 50° C.
The amino acid dissolved over the course of approx. 1 hr, forming a clear solution.
The solution was slightly cooled and concentrated on the rotovap.
Fresh anhydrous THF (400 mL) was added to the residue and the solution was re-evaporated on the rotovap to give a colorless solid, which was dissolved in 300 mL anhydrous THF, transferred to a 4 L beaker and precipitated by the slow addition of 1.5 L of anhydrous heptane.The pure NCA was isolated by suction filtration and dried in vacuo. 75.31 g (95.4% yield) of Glu(OBn) NCA was isolated as a colorless, crystalline solid. ¹H NMR (CDCl₃) δ 7.36 (5H), 6.40 (1H), 5.14 (2H), 4.40 (1H), 2.60 (2H), 2.22 (2H).

References:

US2013/280306,2013,A1 Location in patent:Paragraph 0394; 0395

1676-73-9
387 suppliers
$6.00/5g

3190-71-4
161 suppliers
$8.00/250mg

References

32315-10-9 Synthesis