反应详情

To a suspension of 5-bromo-2-furancarboxylic acid (5.00 g) and N-hydroxysuccinimide (3.31 g) in acetonitrile (50 ml) was added 1-ethyl-3-(3′-dimethylaminopropyl)carbodiimide hydrochloride (5.52 g) at room temperature, and the mixture was stirred for 2 hours. To the reaction mixture was added a suspension of N,O-dimethylhydroxyl-amine hydrochloride (2.81 g) and triethylamine (10 ml) in acetonitrile (20 ml), and the mixture was stirred for 1 hour. To the reaction mixture were added 1,8-diazabicyclo-[5.4.0]-7-undecene (4.3 ml) and DMF (50 ml), and the mixture was stirred for 3 hours and concentrated under reduced pressure. To the residue was added water, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated sodium chloride solution, dried with magnesium sulfate and concentrated under reduced pressure. The residue was separated and purified with column chromatography (ethyl acetate/hexane=1:4→1:3→1:2) to give N-methyl-N-methoxy-5-bromofuran-2-carboxamide (2.77 g) as pale yellow oil.

1. additionTo the reaction mixture was added
2. stirringthe mixture was stirred for 1 hour
3. stirringthe mixture was stirred for 3 hours
4. concentrationconcentrated under reduced pressure
5. additionTo the residue was added water
6. extractionthe mixture was extracted with ethyl acetate
7. washThe organic layer was washed with saturated sodium chloride solution
8. dry with materialdried with magnesium sulfate
9. concentrationconcentrated under reduced pressure
10. customThe residue was separated
11. custompurified with column chromatography (ethyl acetate/hexane=1:4→1:3→1:2)