Propargyl bromide → 2-[(4-Methoxy-2,3,6-trimethyl-benzenesulfonyl)-prop-2-ynyl-amino]-3-phenyl-propionic acid methyl ester

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Reaction Steps

A DMF (8 mL) solution of 2-(4-Methoxy-2,3,6-trimethyl-benzenesulfonylamino)-3-phenyl-propionic acid methyl ester (prepared according to example 2, step I) (200 mg) was cooled to 0° C. and then propargyl bromide (80%, 0.07 mL, 0.61 mmol) and Cs2CO3 (200 mg, 0.61 mmol) were added under an atmosphere of N2. The ice bath was removed and the reaction mixture was stirred at room temperature for 12 h. The mixture was partitioned between ether and water, the ether layer was separated, dried (Na2SO4) and concentrated. The residue was purified by silica gel column chromatography using ethyl acetate and hexane (1:3) as eluent to obtain 2-[(4-Methoxy-2,3,6-trimethyl-benzenesulfonyl)-prop-2-ynyl-amino]-3-phenyl-propionic acid methyl ester (185 mg, 85%) as a solid. 1H NMR (CDCl3, 400 MHz): δ7.20-7.17 (m, 3H), 7.10-7.08 (m, 2H), 6.56 (s, 1H), 4.42-4.29 (m, 3H), 3.86 (s, 3H), 3.56 (s, 3H), 3.32 (dd, 1H), 3.26 (dd, 1H), 2.66, 2.35 (2s, 6H), 2.21 (t, 1H), 2.08(s, 3H).

Provenance & Evidence