反应详情

To 5-(ethoxycarbonyl)thiophen-2-carboxylic acid (250 mg) is added successively methylene chloride (3.0 mL), N,N-dimethylethylenediamine (100 mg), 1-hydroxybenzotriazole (205 mg), triethylamine (610 mg), and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (290 mg). The mixture is stirred at room temperature overnight. The reaction mixture is diluted with chloroform and thereto is added a saturated sodium hydrogencarbonate solution. After stirring, the organic layer is separated and concentrated in vacuo. The residue is purified by flash column chromatography on NH-silica gel (Solvent; ethyl acetate) to give ethyl 5-[[[2-(dimethylamino)ethyl]amino]carbonyl]thiophen-2-carboxylate (160 mg, yield; 53%) as brown crystals. MS (APCI) m/z: 271 [M+H]+

1. stirringAfter stirring
2. customthe organic layer is separated
3. concentrationconcentrated in vacuo
4. customThe residue is purified by flash column chromatography on NH-silica gel (Solvent; ethyl acetate)