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N-Boc-L-tert-Leucine is a white to slightly yellow crystalline powder. The carboxyl group in its structure can be condensed with alcohol compounds under the catalysis of acid or base to obtain the corresponding ester derivatives. This substance can be used for the synthesis of amino acid drugs due to the various chemical transformation properties of its amine and carboxyl groups. The Boc protective group is able to protect the amino group of the amino acid from non-specific reactions with other reactants. This compound is a derivative of L-tert-Leucine, which is a non-polar amino acid. Its tert-butyl group exhibits significant hydrophobicity and steric hindrance, enabling effective control of molecular conformation in chemical reactions, leading to the formation of chiral compounds. As a crucial chiral intermediate, L-tert-leucine is widely employed in the synthesis of anti-cancer, anti-viral, and biological inhibitors. Additionally, L-tert-leucine serves as an essential additive in the food and cosmetic industry.

White crystalline powder

Atazanavir Related Compound A

N-Boc-L-tert-Leucine was used as a precursor in the synthesis of a precatalyst.

reaction type: Boc solid-phase peptide synthesis
reaction type: C-H Activation
reagent type: ligand
reaction type: Peptide Synthesis

Step A: Synthesis of N-Boc-L-tert-Leucine 1. add triethylamine (56mL, 0.4mol) to a methanol (150mL) suspension of L-tert-leucine (26.1g, 0.2mol) at 0°C. 2. slowly add di-tert-butyl dicarbonate (48g, 0.22mol) to a methanol (40mL) solution of N-Boc-L-tert-leucine. 2. a solution of di-tert-butyl dicarbonate (48 g, 0.22 mol) in methanol (40 mL) was added slowly to the above mixture, controlling the reaction temperature between 0 and 5°C. 3. The reaction mixture was stirred at room temperature overnight. 4. Upon completion of the reaction, the solvent was removed under vacuum. 5. The residue was dissolved in ethyl acetate (200 mL) and the organic layer was washed with 10% w/v aqueous citric acid (3 x 100 mL). 6. The organic layer was dried with anhydrous magnesium sulfate, filtered and the solvent was removed in vacuum to afford N-Boc-L-tert-leucine as a light yellow oil (48.9 g, yield >100% with residual solvent). Product characterization: 1H NMR (CDCl3): δ/ppm 9.20 (1H, bs, NH), 5.10 (1H, m, CH), 4.15 (1H, m, CH), 1.45 (9H, s, tert-butyl in Boc), 1.00 (9H, s, tert-butyl in tert-leucine).

[1] Patent: US6716878, 2004, B1. Location in patent: Page column 14
[2] Patent: US6716878, 2004, B1. Location in patent: Page column 62
[3] Patent: CN107325025, 2017, A. Location in patent: Paragraph 0086; 0087
[4] Patent: WO2005/73195, 2005, A2. Location in patent: Page/Page column 96-97
[5] Tetrahedron, 2008, vol. 64, # 18, p. 3980 - 3997