Diisopropylethylamine → 3-{[(5-Chloro-thiophene-2-carbonyl)-amino]-methyl}-[1,2,4]oxadiazole-5-carboxylic acid ethyl ester

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Reaction Steps

To a stirred solution of 3-aminomethyl-[1,2,4]oxadiazole-5-carboxylic acid ethyl ester dihydrochloride (555 mg) at r.t. in DMF (10 ml) under an argon atmosphere were added N-ethyldiisopropylamine (1.82 ml), 5-chloro-2-thiophenecarboxylic acid (565 mg) and BOP (1.54 mg). The mixture was stirred over night, then diluted with EtOAc and washed with H2O. The aqueous phase was back extracted with EtOAc and brine, dried over MgSO4, filtered and concentrated. The crude product was purified by column chromatography (silica gel; gradient: cyclohexane->cyclohexane/EtOAc 1:1) to give 3-{[(5-chloro-thiophene-2-carbonyl)-amino]-methyl}-[1,2,4]oxadiazole-5-carboxylic acid ethyl ester (586 mg) as off-white solid. MS 316.0 ([M+H]+)

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