Synthesis of aza-phenylalanine, aza-tyrosine, and aza-tryptophan precursors via hydrazine alkylation

Aza-amino acid precursors with an aromatic side chain were synthesized, using hydrazine alkylation. This synthetic pathway avoided use of hydrogen gas and expensive hydrogenation catalysts. For the optimization of this alkylation, reaction various solvents and different reaction conditions were used. Aza-phenylalanine, aza-tyrosine, and aza-tryptophan precursors with different N- and side-chain protecting groups were synthesized starting from N-protected hydrazines.