115731-96-9Relevant articles and documents
A Novel Preparation of Amino Acid Diphenylmethyl Esters and Their Application in Peptide Synthesis
Barlos, Kleomenis,Kallitsis, John,Mamos, Petros,Patrianakou, Stella,Stavropoulos, Georg
, p. 633 - 636 (2007/10/02)
Trityl amino acid diphenylmethyl esters 2 were prepared by Mitsunobu condensation of tritylamino acids 1 with diphenylmethanol using excess triphenylphosphane and diethyl azodicarboxylate.The esters 2 were converted into the corresponding p-toluenesulfonates 3 on treatment with p-toluenesulfonic acid.The removal of the N-trityl group in the presence of the diphenylmethyl ester group is studied by the preparation of leucine-enkephalin (12).Best selectivity is obtained when 1-hydroxybenzotriazole in trifluoroethanol is used as detritylation reagent.