Diisopropylethylamine → 2-[(7-Hydroxy-benzo[b]thiophene-6-carbonyl)-amino]-2-methyl-propionic acid methyl ester

Participants

Reaction Steps

To a solution of 1.40 g 7-hydroxy-benzo[b]thiophene-6-carboxylic acid in 20 ml N,N-dimethylformamide were added 0.21 g 1-hydroxy-benzotriaziole and 1.42 g 2-amino-2-methyl-propionic acid methyl ester hydrochloride. At 0° C. 6.4 ml (4.99 g) ethyl-diiso-propyl-amine and 2.22 g (3-dimethylamino-propyl)-ethyl-carbodiimide hydrochloride were added. After 2 days at room temperature the reaction mixture was concentrated in vacuo, and the resulting residue was diluted with ethyl acetate and washed with brine. The organic layer was dried over magnesium sulphate and concentrated. The resulting residue was purified by flash chromatography (silica, heptane/ethyl acetate) to afford 0.84 g 2-[(7-hydroxy-benzo[b]thiophene-6-carbonyl)-amino]-2-methyl-propionic acid methyl ester.

Provenance & Evidence