Lithium hydroxide, monohydrate → 4-[[[5-Methoxy-3-[(1-methylethyl)thio]benzo[b]thien-2yl]carbonyl]amino]benzoic acid

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Reaction Steps

A suspension of lithium hydroxide-monohydrate (20 mg, 0.48 mmol) and methyl 4-[[[5-methoxy-3-[(1-methylethyl)thio]benzo[b]thien-2yl]carbonyl]amino]benzoate (67 mg, 0.16 mmol) in 4 mL of methanol and 2 mL of water is heated at reflux for 1.5 hours. The reaction mixture is cooled to room temperature and then diluted with ethyl acetate and washed sequentially with 1N HCl, water, and brine. The organic layer is dried over MgSO4. Filtration followed by concentration in vacuo and recrystallization from ethyl acetate: hexane gives 4-[[[5-methoxy-3-[(1-methylethyl)thio]benzo[b]thien-2yl]carbonyl]amino]benzoic acid in 78% yield; mp=241°-245° C. dec.

Provenance & Evidence