title: An efficient method for the synthesis of phenacyl ester-protected dipeptides using neutral alumina-supported sodium carbonate 'Na2 CO3 /n-Al2 O3 '.
abstract: In the synthesis of dipeptides (Boc-AA(1)-AA(2)-OPac: AA(1) and AA(2) represent amino acids) protected by phenacyl (Pac) ester, amines and solid bases as the base for the conversion of the trifluoroacetic acid (TFA) salt of the amino component (TFA·H-AA(2)-OPac) into the corresponding free amino component (H-AA(2)-OPac) were examined. The synthesis of a dipeptide (Boc-Ala-Gly-OPac) using amines for the conversion afforded an unsatisfactory yield with by-products. On the other hand, the use of neutral alumina-supported Na(2) CO(3) (Na(2)CO(3) /n-Al(2)O(3)) as a solid base for the conversion provided the dipeptide in a quantitative yield without by-products. The application of Na(2)CO(3) /n-Al2 O3 to the synthesis of some dipeptides protected by Pac ester gave the desired peptides in excellent yields.
authors: Department of Chemistry, The Jikei University School of Medicine, 8-3-1 Kokuryo-cho, Choufu-shi, Tokyo, 182-8570, Japan.
authors: Chikao
authors: C
authors: Hashimoto
authors: Kazuhiro
authors: K
authors: Sugimoto
authors: Youhei
authors: Y
authors: Takahashi
authors: Mitsuo
authors: M
authors: Kodomari
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry*; D004151:Dipeptides / Q000138:chemical synthesis* / Q000737:chemistry; D004952:Esters / Q000138:chemical synthesis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy
chemical_list: D002254:Carbonates; D004151:Dipeptides; D004952:Esters; C005686:sodium carbonate; D000537:Aluminum Oxide
keywords: amine; neutral alumina-supported sodium carbonate; peptide synthesis; phenacyl ester; solid base