PREPARATION OF N-ALPHA-BOC 4-O-DIETHYLPHOSPHO-L-AZATYROSINE, A REAGENT POTENTIALLY USEFUL FOR THE SYNTHESIS OF SIGNAL-TRANSDUCTION RELATED PEPTIDES

Preparation of the phosphorylated azatyrosine analogue, 2(S)-Na-Boc-3- [5'-(diethyl phosphoryloxy)-2'-pyridyl]propionate (3), is reported. Th is compound is designed for the solid-phase synthesis of cell signal t ransduction peptides containing a phosphotyrosyl reside bearing a nitr ogen atom in the tyrosyl aromatic ring. An important aspect of the syn thetic approach is the use of diethyl phosphate functionality for phen olic hydroxyl protection during palladium-mediated coupling.