반응 #309639

반응 방정식

NaOEt

EtOH

5-bromo-1-methyl-1H-indole

oxalyl chloride

THF

HCl

methyl iodide

5-bromo-indole

DMF

NaH

→

product

수율 86.0%

3-Benzofuran-3-yl-4-(5-bromo-1-methyl-1H-indol-3-yl)-pyrrole-2,5-dione

수율 86.0%

용매

Et2O

반응 조건

후처리

1. 1
   추출the solution was extracted with ethyl acetate
2. 2
   추출The ethyl acetate extract
3. 3
   세척was washed with water and brine
4. 4
   건조dried over anhydrous Na2SO4
5. 5
   농축concentrated in vacuo
6. 6
   여과The residue was filtered through silica gel (ethyl acetate:hexane; 1:4)
7. 7
   기타The product, 5-bromo-1-methyl-1H-indole, was subjected to further reaction without additional purification
8. 8
   workup.ADDITIONwas added dropwise
9. 9
   온도to warm to room temperature
10. 10
    workup.STIRRINGstirred overnight
11. 11
    온도It was then cooled to −60° C.
12. 12
    온도to warm to room temperature
13. 13
    기타The reaction was quenched by the addition of water
14. 14
    workup.ADDITIONdiluted with ethyl acetate
15. 15
    기타The organic layer was separated
16. 16
    건조dried over anhydrous Na2SO4
17. 17
    농축concentrated
18. 18
    기타The residue was purified by column chromatography (ethyl acetate:hexane; 1:3)

실험 절차

To a solution of 5-bromo-indole (3.30 g, 11.73 mmol) in dry DMF (15 mL) cooled with an ice bath was added NaH (55% suspension in mineral oil, 1.02 g, 23.46 mmol), followed by methyl iodide (2.50 g, 17.60 mmol) after which the reaction mixture was allowed to warm to room temperature. After 6 h the reaction mixture was poured into ice-water; 1N HCl was added to adjust the pH to about 4, and the solution was extracted with ethyl acetate. The ethyl acetate extract was washed with water and brine, then dried over anhydrous Na2SO4, and concentrated in vacuo. The residue was filtered through silica gel (ethyl acetate:hexane; 1:4). The product, 5-bromo-1-methyl-1H-indole, was subjected to further reaction without additional purification. To a solution of 5-bromo-1-methyl-1H-indole in Et2O (20 mL) cooled to 0° C. a 2.0 M solution of oxalyl chloride in THF (17.0 mL, 34.0 mmol) was added dropwise. The reaction was then stirred for 0.5 h at 0° C. and allowed to warm to room temperature and stirred overnight. It was then cooled to −60° C. and a 21% solution of NaOEt in EtOH (13.50 mL, 45.70 mmol) was added, after which the reaction mixture was allowed to warm to room temperature. The reaction was quenched by the addition of water and diluted with ethyl acetate. The organic layer was separated, dried over anhydrous Na2SO4 and concentrated. The residue was purified by column chromatography (ethyl acetate:hexane; 1:3) to give a product (2.92 g, 86%).

출처