反应详情

Methyl 3-(2-formylpyrrol-1-yl)benzoate (5.0 g) was added to a mixture of hydroxylamine hydrochloride (1.5 g) and 28% methanolic sodium methoxide (4.2 g) in methanol (50 ml) and the mixture was stirred for 4 hours at ambient temperature. The solvent was removed by concentration and the residue was dissolved in a mixture of ethyl acetate and water. The mixture was adjusted to pH 2 with 6N-hydrochloric acid. The separated organic layer was washed with brine, dried over magnesium sulfate and evaporated in vacuo. The residue was subjected to column chromatography on silica gel eluting with a mixture of chloroform and ethyl acetate (19:1). The first eluted fractions containing the desired product were collected and evaporated in vacuo and the residue was triturated with a mixture of diisopropyl ether and n-hexane to give methyl 3-[(E)-2-hydroxyiminomethylpyrrol-1-yl]benzoate (Compound A) (0.8 g). The further eluted fractions containing the desired product were collected and evaporated in vacuo to give methyl 3-[(Z)-2-hydroxyiminomethylpyrrol-1-yl]benzoate (Compound B) (1.43 g) as an oil.

1. customThe solvent was removed by concentration
2. dissolutionthe residue was dissolved in a mixture of ethyl acetate and water
3. washThe separated organic layer was washed with brine
4. dry with materialdried over magnesium sulfate
5. customevaporated in vacuo
6. additionThe residue was subjected to column chromatography on silica gel eluting with a mixture of chloroform and ethyl acetate (19:1)
7. washThe first eluted fractions
8. additioncontaining the desired product
9. customwere collected
10. customevaporated in vacuo
11. customthe residue was triturated with a mixture of diisopropyl ether and n-hexane