Fmoc-Asp(OtBu)-OH CAS 71989-14-5 Purity >99.0% (HPLC) Factory

Fmoc-L-Aspartic Acid β-tert-Butyl Ester (Fmoc-Asp(OtBu)-OH) (CAS: 71989-14-5) is a chemical intermediate, commonly used in polypeptide synthesis process, for amino acid protection. Fmoc-amino acids, used in peptide synthesis, used as an organic synthesis intermediate, pharmaceutical intermediate, biochemical reagent or chemical reagent.
Preparation: Add 581g of tert-Butyl Acetate and 133g of Aspartic Acid to a ML three-mouth bottle, stir, and add of perchloric acid dropwise, reaction at 10℃ for 48 hours, cooled to 0℃, then added 700ml of water, extracted (the remaining tert-Butyl Acetate as solvent extraction), neutralized with Na2CO3 to pH = 7, liquid separation, the tert-Butyl Acetate layer was concentrated under reduced pressure to obtain a mixture of Asp(OtBu)2, Asp(OtBu) and Asp-OtBu oil, which was combined with the aqueous layer to be used. The resulting mixture was transferred to 125 ml three bottles, G cuso4 · 5H2O was added, and the pH was adjusted to 3 with concentrated hydrochloric acid. The mixture was stirred and heated to 50℃. For 12 hours to prepare Cu[Asp(OtBu)]x. (x = 1~2); Then down to room temperature, add 116.2G tetramethylethylenediamine and 300ml dioxane, and then adjust the pH to 8~9 with triethylamine to prepare Asp(OtBu); then add 82gFmoc-OSu into Asp(OtBu), maintain pH 8~9, react for 8 hours, then extract with ethyl acetate, acidify, wash with water, vacuum distillation, crystallization, drying, 85g of Fmoc-L-aspartic acid beta-tert-butyl ester was obtained in a yield of 20.7%. By HPLC analysis of Fmoc-L-Aspartic Acid β-tert-Butyl Ester.