反应详情

To a solution of phosphorus oxychloride (8.3 ml) and N,N-dimethylformamide (70 ml) was added methyl 4-acetoxy-3-(pyrrol-1-yl)benzoate (11.7 g) at ambient temperature and the mixture was stirred for 20 hours at the same temperature. The reaction mixture was poured into water and extracted with ethyl acetate. The extract layer was washed with water, dried over magnesium sulfate and evaporated in vacuo. The residue was dissolved in tetrahydrofuran. To the solution was added 28% methanolic sodium methoxide (9.7 ml) under ice-cooling and the mixture was stirred for 30 minutes at the same temperature. To the mixture was added acetic acid (6 ml) and evaporated in vacuo. To the residue was added a mixture of ethyl acetate and water, and adjusted to pH 7 with 20% aqueous potassium carbonate solution. The separated organic layer was washed with water, dried over magnesium sulfate and evaporated in vacuo. The residue was crystallized from toluene, collected by filtration and the precipitate was washed with ether to give methyl 3-(2-formylpyrrol-1-yl)-4-hydroxybenzoate (7.89 g).

1. extractionextracted with ethyl acetate
2. washThe extract layer was washed with water
3. dry with materialdried over magnesium sulfate
4. customevaporated in vacuo
5. dissolutionThe residue was dissolved in tetrahydrofuran
6. additionTo the solution was added 28% methanolic sodium methoxide (9.7 ml) under ice-
7. temperaturecooling
8. stirringthe mixture was stirred for 30 minutes at the same temperature
9. additionTo the mixture was added acetic acid (6 ml)
10. customevaporated in vacuo
11. additionTo the residue was added
12. additiona mixture of ethyl acetate and water
13. washThe separated organic layer was washed with water
14. dry with materialdried over magnesium sulfate
15. customevaporated in vacuo
16. customThe residue was crystallized from toluene
17. filtrationcollected by filtration
18. washthe precipitate was washed with ether