1,2-Dichloroethane → N-(2,6-Dimethoxybenzoyl)-(O-benzyl)-L-tyrosine Methyl Ester

Participants

Reaction Steps

EDC (212 mg, 1.1 mmol) was added to a solution of (O-benzyl)tyrosine methyl ester hydrochloride (322 mg, 1 mmol), 2,6-dimethoxybenzoic acid (182 mg, 1 mmol), HOBT (149 mg, 1.1 mmol) and NMM (242 μl, 2.2 mmol) in DCM (10 ml). The mixture was stirred at room temperature overnight, then diluted with DCM (100 ml), washed with 10% citric acid (20 ml), saturated sodium bicarbonate solution (20 ml) and brine (20 ml), dried (Na2SO4) and evaporated under reduced pressure. The residue was purified by column chromatography (SiO2; EtOAc/hexane, 60:40) to give the title compound as a colourless gum (392 mg, 87%). δH (CDCl3) 7.44-7.31 (5H, m, OCH2Ph), 7.29 (1H, t, 18.4 Hz, Ar(OMe)H), 7.14 (2H, d, 18.7 Hz, CH2Ar(O)H), 6.88 (2H, d, J 8.7 Hz, CH2Ar(O)H), 6.55 (2H, d, J 8.4 Hz, Ar(OMe)H), 6.36 (1H, br d, 17.4 Hz, CONH), 5.11 (1H, dt, J 7.5, 5.2 Hz, CHαtyr) 5.02 (2H, s, OCH2Ph), 3.80 (6H, s, 2×ArOMe), 3.72 (3H, s, CO2Me), 3.29 (1H, dd, J 5.5, 14.0 Hz. CHCHAHBAr) and 3.16 (1H, dd, J 4.9, 14.0 Hz, CHCHAHBAr); m/z (ESI, 15V) 450 (Mh+).

Provenance & Evidence