Ethyl methyl sulfide → 3-Phenyl-2-prop-2-ynylamino-propionic acid methyl ester

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Reaction Steps

To a solution of 2-[(4-Methoxy-2,3,6-trimethyl-benzenesulfonyl)-prop-2-ynyl-amino]-3-phenyl-propionic acid methyl ester (150 mg, 0.349 mmol) in anhydrous dichloroethane (1.5 mL), trifluoroacetic acid (3.5 mL) and ethyl methyl sulfide (0.16 mL, 1.75 mmol) were added. The reaction mixture was stirred at room temperature under a N2 atmosphere for 12 h. Excess of solvents were removed under reduced pressure and the residue was extracted between saturated NaHCO3 solution and ethyl acetate. The organic layer was separated, dried (Na2SO4), concentrated. The crude product was purified by silica gel column chromatography using ethyl acetate and hexane (1:3) as eluent to obtain 3-Phenyl-2-prop-2-ynylamino-propionic acid methyl ester as a thick syrup, 70 mg (92%). 1H NMR (CDCl3, 400 MHz): δ7.32-7.19 (m, 5H), 3.78 (t, 1H), 3.68 (s, 3H), 3.40 (ABq, 2H), 3.03 (dd, 1H), 2.98 (dd, 1H), 1.99 (t, 1H).

Provenance & Evidence