Methyl 2-nitropropanoate → (+/-)-3-(5-ethoxy-1H-indol-3-yl)-2-methyl-2-nitro-propionic acid methyl ester

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Reaction Steps

A mixture of (5-ethoxy-1H-indol-ylmethyl)-dimethyl-amine (2.18 g, 10 mmol) and commercially available methyl 2-nitro-propionate (1.60 g, 12 mmol, 1.2 equiv) in dry toluene (17 ml) is refluxed. When TLC (toluene-acetone, 9:1) indicates the absence of starting material the mixture is cooled and is diluted with chloroform (35 ml). It is subsequently washed with 10% aqueous HCl (2×10 ml), water (10 ml), 5% aqueous NaOH (2×10 ml), water (10 ml), and 20% aqueous Na2SO4 (10 ml), is dried, and the solvents are removed under reduced pressure. The residue is purified by column chromatography (light petroleum-ethyl acetate, 4:1→7:3) to give (+/−)-3-(5-ethoxy-1H-indol-3-yl)-2-methyl-2-nitro-propionic acid methyl ester (2.07 g, 68%) as a white solid. M.p. 80-82° C. (from ethyl acetate-hexane).

Provenance & Evidence