反应详情

To dry toluene (4 ml) under an inert atmosphere at 0° C. was added a toluene solution of trimethylaluminium (1.90 ml, 3.79 mmol, 2 M solution). A solution of ethylenediamine (0.25 ml, 3.79 mmol) in toluene (1.5 ml) was then added dropwise and the reaction mixture was then allowed to warm to room temperature and stirred for 100 min at this temperature before being re-cooled to 0° C. To this mixture was added dropwise a solution of (4-bromo-3-chloro-phenylamino)-acetic acid ethyl ester (0.56 g, 1.90 mmol) in toluene (3 ml). The reaction mixture was then heated at 95° C. for 45 min and then cooled first to room temperature and finally to 0° C. The mixture was quenched by dropwise addition of methanol (1 ml) and when all gas evolution had ceased the mixture was diluted with water and extracted twice with ethyl acetate. The combined organic extracts were dried over sodium sulphate, filtered and concentrated in vacuo. The residue was purified by flash chromatography (SiO2: dichloromethane/methanol=gradient 100:0-98:2) to yield a yellow gum; MS (ISP): 292.1, 290.0, 288.1 ([M+H]+.).

1. temperaturebefore being re-cooled to 0° C
2. temperatureThe reaction mixture was then heated at 95° C. for 45 min
3. temperaturecooled first to room temperature and finally to 0° C
4. customThe mixture was quenched by dropwise addition of methanol (1 ml) and when all gas evolution
5. additionwas diluted with water
6. extractionextracted twice with ethyl acetate
7. dry with materialThe combined organic extracts were dried over sodium sulphate
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customThe residue was purified by flash chromatography (SiO2: dichloromethane/methanol=gradient 100:0-98:2)
11. customto yield a yellow gum