N-Boc-L-tyrosine is an N-Boc-protected form of L-Tyrosine (T899975). L-Tyrosine is an essential amino acid that exhibits in vitro antioxidant and antiradical activities. L-Tyrosine is used as a precursor to synthesize catecholamines (e.g. Norepinephrine HCl [N674500]) in human keratinocytes, and also for the synthesis of proteins and thyroid hormones.
In a dry 50 mL round-bottomed flask, (2S)-2-amino-3-(4-hydroxyphenyl)propanoic acid ( 200 mg) was dissolved in dry 1,4 -dioxane ( 10 mL) and H2O (5 mL) ( 2:1 ). NaOH ( 1 M, 5 mL, 5 mmol, 4.5 eq.) and Boc2O ( 0.28 mL, 1.21 mmol) were then added sequentially to the solution. The resulting reaction mixture was stirred at room temperature for 3 h. The progress of the reaction was monitored by LCMS and after waiting for the end of the reaction the reaction solution was acidified with 2 M HCl to a pH of about 2 - 3. The resulting reaction mixture was extracted three times with ethyl acetate ( 3 25 mL), all the organic layers were combined and the organic layer was washed with brine, the organic layer was separated out and dried with anhydrous Na2SO4, the organic layer was filtered to remove the drying agent, and the resulting organic layer was dried with anhydrous Na2SO4. The organic layer was separated and dried with anhydrous Na2SO4, the organic layer was filtered to remove the desiccant, and the resulting filtrate was concentrated under vacuum to remove the organic solvent, and the crude product was separated and purified by silica gel column chromatography to obtain the target product molecule, N-tert-butoxycarbonyl-L-tyrosine.
