反应详情

A mixture of 4-nitrophenoxy acetic acid (2.25 g, 11.4 mmole), acetamideoxime, triethylamine hydrochloride (3.85 g, 27.62 mmole), EDCI.HCl (4.37 g, 22.79 mmole) and diisopropylethylamine (7.42 g, 57.40 mmole) in anhydrous THF (250 ml) was refluxed for 18 h. The unhomogenous brown colored reaction mixture was quenched with water and extracted with EtOAc (3×300 mL). The combined organic layers washed successively with aqueous NaHCO3, brine and dried over anhydrous Na2SO4. Removal of solvent and purified by chromatographic purification provided 5-[(4-nitrophenoxy)methyl]-3-methyl-1,2,4-oxadiazole (1.62 g, 60%). 1H NMR (CDCl3): δ 8.24 (d, 2H, J=8.8 Hz), 7.08 (d, 2H, J=8.8 Hz), 5.36 (s, 2H), 2.44 (s, 3H).

1. temperaturewas refluxed for 18 h
2. customThe unhomogenous brown colored reaction mixture was quenched with water
3. extractionextracted with EtOAc (3×300 mL)
4. washThe combined organic layers washed successively with aqueous NaHCO3, brine
5. dry with materialdried over anhydrous Na2SO4
6. customRemoval of solvent
7. custompurified by chromatographic purification