Hydrochloric Acid → Methyl 4-[[[5-Methoxy-3-(1-methylethoxy)benzo[b]thien-2-yl]carbonyl]amino]benzeneacetate

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Reaction Steps

To 5-methoxy-3-(1-methylethoxy)benzo[b]thiophene-2-carboxylic acid (500 mg, 2.0 mmoles) in 20 mL of dry tetrahydrofuran is added oxalyl chloride (262 μL, 3.0 mmoles) followed by one drop of dimethylformamide. The HCl salt of methyl 4-aminophenylacetate (605 mg, 3.0 mmoles) is added, followed by triethylamine (1.4 mL, 10 mmoles). The mixture is stirred at room temperature overnight. The mixture is partitioned between ethyl acetate and 1N HCl. The organic layer is washed with water, then brine. The organic layer is next dried over magnesium sulfate, filtered, and concentrated in vacuo. The crude product is purified by flash chromatography, eluting with a gradient of 1:1 ethyl acetate:hexane to only ethyl acetate to provide 692 mg (84%) of product; mp 111°-113° C.

Provenance & Evidence