This dissertation includes four chapters. Chapter 1 includes the introduction and literature review. Chapter 2 covers the enzymatic synthesis of tryptophan via anthranilic acid analogues. Chapter 3 covers the nitration and resolution of tryptophan and synthesis of tryptophan derivatives. Chapter 4 covers the synthesis of sulfenyl chloride derivatives.Tryptophan is important in many aspects in the studies of proteins and also serves as precursors for important compounds. The enzymatic synthesis of tryptophan analogues from anthranilic acid analogues is important and could provide a more efficient route for incorporation of non-canonical amino acids onto proteins. Nitration of tryptophan is also important because it provides a synthetic route for synthesizing other derivatives of tryptophan. Sulfenyl chloride derivatives can be used for labeling proteins and the tryptophan analogues can be determined by mass spectrometry analysis with proteins with a limited number of tryptophan residues makes this application useful.