反应详情

To a solution of ethyl 7-amino-1H-indole-2-carboxylate (3 g) in pyridine (30 mL) was added 1-methyl-1H-imidazole-2-sulfonyl chloride (3.6 g) under ice-cooling, and the mixture was stirred for 1 hr. The reaction mixture was concentrated, and the residue was dissolved in ethyl acetate. The solution was washed with water. The ethyl acetate layer was washed with 1N hydrochloric acid, saturated brine and saturated aqueous sodium hydrogencarbonate solution, dried (MgSO4), and concentrated. The obtained residue was dissolved in DMF (30 mL), potassium carbonate (2.1 g) and methyl iodide (2.1 g) were added at room temperature, and the mixture was stirred for 3 hr at room temperature. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with 1N hydrochloric acid, saturated brine and saturated aqueous sodium hydrogencarbonate solution, dried (MgSO4), and concentrated. The obtained residue was subjected to silica gel column chromatography to give the title compound (3.0 g, yield 59%) as white crystals from a fraction eluted with ethyl acetate:hexane=50:50. melting point 120° C.

1. temperaturecooling
2. concentrationThe reaction mixture was concentrated
3. dissolutionthe residue was dissolved in ethyl acetate
4. washThe solution was washed with water
5. washThe ethyl acetate layer was washed with 1N hydrochloric acid, saturated brine and saturated aqueous sodium hydrogencarbonate solution
6. dry with materialdried (MgSO4)
7. concentrationconcentrated
8. dissolutionThe obtained residue was dissolved in DMF (30 mL)
9. additionpotassium carbonate (2.1 g) and methyl iodide (2.1 g) were added at room temperature
10. stirringthe mixture was stirred for 3 hr at room temperature
11. additionWater was added to the reaction mixture
12. extractionthe mixture was extracted with ethyl acetate
13. washThe ethyl acetate layer was washed with 1N hydrochloric acid, saturated brine and saturated aqueous sodium hydrogencarbonate solution
14. dry with materialdried (MgSO4)
15. concentrationconcentrated