反应详情

5-(3-Chloro-thiophen-2-yl)-[1,2,4]-oxadiazol-3-ylamine: A solution of N-cyano-3-chloro-thiophene-2-carboxylic acid amide (467.5 mg, 2.5 mmol), hydroxylamine hydrochloride (174 mg, 2.5 mmol) in pyridine (5 mL) was heated at 100° C. for 8 h. It was cooled and poured into water (80 mL), and the mixture was extracted with ethyl acetate (3×20 mL). The combined organic layer was washed with water, 1N HCl, dried with Na2SO4, and concentrated. The crude residue was purified by column chromatography (hexane:ethyl acetate, 10:1) to yield 189 mg (37%) of title compound. 1H NMR (CDCl3): 7.56 (d, J=5.4 Hz, 1H), 7.09 (d, J=5.4 Hz, 1H), 4.49 (brs, 2H).

1. temperatureIt was cooled
2. extractionthe mixture was extracted with ethyl acetate (3×20 mL)
3. washThe combined organic layer was washed with water, 1N HCl
4. dry with materialdried with Na2SO4
5. concentrationconcentrated
6. customThe crude residue was purified by column chromatography (hexane:ethyl acetate, 10:1)