Hydrochloric Acid → 3-(4-Acetoxy-2,6-dimethyl-phenyl)-2-tert-butoxycarbonylamino-propionic acid

Reaction equation

[C:1]([O:5][C:6]([NH:8][CH:9]([CH2:13][C:14]1[C:19]([CH3:20])=[CH:18][C:17]([OH:21])=[CH:16][C:15]=1[CH3:22])[C:10]([OH:12])=[O:11])=[O:7])([CH3:4])([CH3:3])[CH3:2].[OH-].[Na+].[C:25](OC(=O)C)(=[O:27])[CH3:26].Cl>>[C:25]([O:21][C:17]1[CH:16]=[C:15]([CH3:22])[C:14]([CH2:13][CH:9]([NH:8][C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:7])[C:10]([OH:12])=[O:11])=[C:19]([CH3:20])[CH:18]=1)(=[O:27])[CH3:26]

Participants

Reactant 4

HCID 313Hydrochloric Acid

HCID 7918Acetic Anhydride

HCID 14798Sodium Hydroxide

HCID 13656656Boc-L-2,6-Dimethyltyrosine

Product 1

HCID 221476663-(4-Acetoxy-2,6-dimethyl-phenyl)-2-tert-butoxycarbonylamino-propionic acid

Procedure

To a solution of 0.77 g (2.5 mmol) of 2-tert-Butoxycarbonylamino-3-(4-hydroxy-2,6-dimethyl-phenyl)-propionic acid and 3 mL of 3N sodium hydroxide solution, cooled in an ice bath, was added 0.89 mL (9.4 mmol) of acetic anhydride dropwise over about 30 seconds. After stirring for 2 hours, the mixture was acidified with addition of 4.5 mL of 2N hydrochloric acid. The mixture was extracted twice with ethyl acetate. The combined organics were dried over magnesium sulfate and concentrate to a clear oil. The title product was used for the next reaction without further purification.