Hydrochloric Acid → (S)-2',6'-Dimethyltyrosine hydrochloride

Participants

Reaction Steps

2,6-Dimethyl-(S)-Tyrosine hydrochloride was prepared by deprotecting N-acetyl-2,6-dimethy-(S)-tyrosine methyl ester as follows: In a 100 ml round-bottom flask was placed 3.40 g (13 mmol) of N-acetyl-2,6-dimethyl-(S)-tyrosine methyl ester and 20 mL of 6N hydrochloric acid. The reaction mixture was refluxed under argon for 41/2 hours, cooled and then concentrated under reduced pressure to afford 3.48 g of a white solid; 1H NMR analysis indicated: (δ, CD3OD) 6.35 (s, 2H), 3.90 (t, J=7 Hz, 1H), 3.3-3.0 (m, 2H) and 2.21 (s, 6H). Mass spectrum analysis indicated: (m/e) 209 (M+), 135 (100%) and 91.

Provenance & Evidence